Firefox doesn't control that options that is controlled by the O/S power management. Firefox is a browser not a Control Panel program.

Agree 100%, but it is still happening. I've tried clean boot. I've scanned for malware. I just got the update to "63". When I start Firefox It changes my power plan to balanced.

That doesn't happen to mine and it's updated to 63x64bit firefox. Something isn't right here the browser has no control of the power management that is coming from the O/S most likely. I check with mine but don't recall it showing anything that it can control power management. Is this a laptop or desktop?

This is a desk top.

Set the power options to where you want them. Then;

Start Firefox in Safe Mode {web link} by holding down the <Shift> (Mac=Options) key, and then starting Firefox.

A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?

Firefox in SAFE mode. No Change in behavior. start FF, PP > BAL. Stop FF, PP > HP. All else is normal.

Something does add up here the Browser doesn't have control of the power management only the O/S can do that and I have a Desktop as well and laptop and have no power management issue. It's starting to sound like your browser is corrupted here.

I ran a Refresh just yesterday and it didn't change anything.

Type about:support in the address bar and press Enter. Under the main banner, press the button; Copy Text To Clipboard.. Now in the Reply Box on the forum page, do a right-click in the box and select Paste.

This will show us your system details. No Personal Information Is Collected.

Application Basics

Name: Firefox Version: 63.0 Build ID: 20181018182531 Update Channel: release User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0 OS: Windows_NT 10.0 Multiprocess Windows: 1/1 (Enabled by default) Web Content Processes: 4/4 Enterprise Policies: Inactive Google Key: Found Mozilla Location Service Key: Found Safe Mode: false

Crash Reports for the Last 3 Days

All Crash Reports (including 2 pending crashes in the given time range) Firefox Features

Name: Application Update Service Helper Version: 2.0 ID: aushelper@mozilla.org

Name: Firefox Screenshots Version: 33.0.0 ID: screenshots@mozilla.org

Name: Form Autofill Version: 1.0 ID: formautofill@mozilla.org

Name: Photon onboarding Version: 1.0 ID: onboarding@mozilla.org

Name: Web Compat Version: 2.0.1 ID: webcompat@mozilla.org

Name: WebCompat Reporter Version: 1.0.0 ID: webcompat-reporter@mozilla.org

Extensions

Name: AdBlock Version: 3.20.0 Enabled: true ID: jid1-NIfFY2CA8fy1tg@jetpack

Name: Cookie AutoDelete Version: 2.2.0 Enabled: true ID: CookieAutoDelete@kennydo.com

Name: Dark Mode Ultimate Version: 1.0.1 Enabled: true ID: dark-mode@addons.cool

Name: Enhancer for YouTube™ Version: 2.0.75 Enabled: true ID: enhancerforyoutube@maximerf.addons.mozilla.org

Name: Imagus Version: 0.9.8.65 Enabled: true ID: {00000f2a-7cde-4f20-83ed-434fcb420d71}

Name: Restart Browser Version: 1.2 Enabled: true ID: Restartfirefox@vazextension.com

Name: Smart HTTPS Version: 0.2.5 Enabled: true ID: {b3e677f4-1150-4387-8629-da738260a48e}

Name: Turbo Download Manager (v2) Version: 0.4.1 Enabled: true ID: jid0-dsq67mf5kjjhiiju2dfb6kk8dfw@jetpack

Name: Video DownloadHelper Version: 7.3.5 Enabled: true ID: {b9db16a4-6edc-47ec-a1f4-b86292ed211d}

Name: YouTube™ Flash® Player Version: 2.0.2 Enabled: true ID: jid1-HAV2inXAnQPIeA@jetpack

Security Software

Type: ZoneAlarm Extreme Security Antivirus

Type: ZoneAlarm Extreme Security Anti-Spyware

Type: ZoneAlarm Extreme Security Firewall

Graphics

Features Compositing: Direct3D 11 (Advanced Layers) Asynchronous Pan/Zoom: wheel input enabled; scrollbar drag enabled; keyboard enabled; autoscroll enabled WebGL 1 Driver WSI Info: EGL_VENDOR: Google Inc. (adapter LUID: 000000000000b82c) EGL_VERSION: 1.4 (ANGLE 2.1.0.ae3b5a6552ee) EGL_EXTENSIONS: EGL_EXT_create_context_robustness EGL_ANGLE_d3d_share_handle_client_buffer EGL_ANGLE_d3d_texture_client_buffer EGL_ANGLE_surface_d3d_texture_2d_share_handle EGL_ANGLE_query_surface_pointer EGL_ANGLE_window_fixed_size EGL_ANGLE_keyed_mutex EGL_ANGLE_surface_orientation EGL_ANGLE_direct_composition EGL_NV_post_sub_buffer EGL_KHR_create_context EGL_EXT_device_query EGL_KHR_image EGL_KHR_image_base EGL_KHR_gl_texture_2D_image EGL_KHR_gl_texture_cubemap_image EGL_KHR_gl_renderbuffer_image EGL_KHR_get_all_proc_addresses EGL_KHR_stream EGL_KHR_stream_consumer_gltexture EGL_NV_stream_consumer_gltexture_yuv EGL_ANGLE_flexible_surface_compatibility EGL_ANGLE_stream_producer_d3d_texture EGL_ANGLE_create_context_webgl_compatibility EGL_CHROMIUM_create_context_bind_generates_resource EGL_CHROMIUM_sync_control EGL_EXT_pixel_format_float EGL_KHR_surfaceless_context EGL_ANGLE_display_texture_share_group EGL_ANGLE_create_context_client_arrays EGL_ANGLE_program_cache_control EGL_ANGLE_robust_resource_initialization EGL_ANGLE_create_context_extensions_enabled EGL_EXTENSIONS(nullptr): EGL_EXT_client_extensions EGL_EXT_platform_base EGL_EXT_platform_device EGL_ANGLE_platform_angle EGL_ANGLE_platform_angle_d3d EGL_ANGLE_device_creation EGL_ANGLE_device_creation_d3d11 EGL_ANGLE_experimental_present_path EGL_KHR_client_get_all_proc_addresses EGL_ANGLE_explicit_context WebGL 1 Driver Renderer: Google Inc. -- ANGLE (NVIDIA GeForce GTX 750 Ti Direct3D11 vs_5_0 ps_5_0) WebGL 1 Driver Version: OpenGL ES 2.0 (ANGLE 2.1.0.ae3b5a6552ee) WebGL 1 Driver Extensions: GL_ANGLE_client_arrays GL_ANGLE_depth_texture GL_ANGLE_explicit_context GL_ANGLE_explicit_context_gles1 GL_ANGLE_framebuffer_blit GL_ANGLE_framebuffer_multisample GL_ANGLE_instanced_arrays GL_ANGLE_lossy_etc_decode GL_ANGLE_pack_reverse_row_order GL_ANGLE_program_cache_control GL_ANGLE_request_extension GL_ANGLE_robust_client_memory GL_ANGLE_texture_compression_dxt3 GL_ANGLE_texture_compression_dxt5 GL_ANGLE_texture_usage GL_ANGLE_translated_shader_source GL_CHROMIUM_bind_generates_resource GL_CHROMIUM_bind_uniform_location GL_CHROMIUM_color_buffer_float_rgb GL_CHROMIUM_color_buffer_float_rgba GL_CHROMIUM_copy_compressed_texture GL_CHROMIUM_copy_texture GL_CHROMIUM_sync_query GL_EXT_blend_minmax GL_EXT_color_buffer_half_float GL_EXT_debug_marker GL_EXT_discard_framebuffer GL_EXT_disjoint_timer_query GL_EXT_draw_buffers GL_EXT_frag_depth GL_EXT_map_buffer_range GL_EXT_occlusion_query_boolean GL_EXT_read_format_bgra GL_EXT_robustness GL_EXT_sRGB GL_EXT_shader_texture_lod GL_EXT_texture_compression_dxt1 GL_EXT_texture_compression_s3tc_srgb GL_EXT_texture_filter_anisotropic GL_EXT_texture_format_BGRA8888 GL_EXT_texture_rg GL_EXT_texture_storage GL_EXT_unpack_subimage GL_KHR_debug GL_KHR_robust_buffer_access_behavior GL_NV_EGL_stream_consumer_external GL_NV_fence GL_NV_pack_subimage GL_NV_pixel_buffer_object GL_OES_EGL_image GL_OES_EGL_image_external GL_OES_compressed_ETC1_RGB8_texture GL_OES_depth32 GL_OES_element_index_uint GL_OES_get_program_binary GL_OES_mapbuffer GL_OES_packed_depth_stencil GL_OES_rgb8_rgba8 GL_OES_standard_derivatives GL_OES_surfaceless_context GL_OES_texture_float GL_OES_texture_float_linear GL_OES_texture_half_float GL_OES_texture_half_float_linear GL_OES_texture_npot GL_OES_vertex_array_object OES_compressed_EAC_R11_signed_texture OES_compressed_EAC_R11_unsigned_texture OES_compressed_EAC_RG11_signed_texture OES_compressed_EAC_RG11_unsigned_texture OES_compressed_ETC2_RGB8_texture OES_compressed_ETC2_RGBA8_texture OES_compressed_ETC2_punchthroughA_RGBA8_texture OES_compressed_ETC2_punchthroughA_sRGB8_alpha_texture OES_compressed_ETC2_sRGB8_alpha8_texture OES_compressed_ETC2_sRGB8_texture WebGL 1 Extensions: ANGLE_instanced_arrays EXT_blend_minmax EXT_color_buffer_half_float EXT_frag_depth EXT_sRGB EXT_shader_texture_lod EXT_texture_filter_anisotropic EXT_disjoint_timer_query OES_element_index_uint OES_standard_derivatives OES_texture_float OES_texture_float_linear OES_texture_half_float OES_texture_half_float_linear OES_vertex_array_object WEBGL_color_buffer_float WEBGL_compressed_texture_s3tc WEBGL_compressed_texture_s3tc_srgb WEBGL_debug_renderer_info WEBGL_debug_shaders WEBGL_depth_texture WEBGL_draw_buffers WEBGL_lose_context WebGL 2 Driver WSI Info: EGL_VENDOR: Google Inc. (adapter LUID: 000000000000b82c) EGL_VERSION: 1.4 (ANGLE 2.1.0.ae3b5a6552ee) EGL_EXTENSIONS: EGL_EXT_create_context_robustness EGL_ANGLE_d3d_share_handle_client_buffer EGL_ANGLE_d3d_texture_client_buffer EGL_ANGLE_surface_d3d_texture_2d_share_handle EGL_ANGLE_query_surface_pointer EGL_ANGLE_window_fixed_size EGL_ANGLE_keyed_mutex EGL_ANGLE_surface_orientation EGL_ANGLE_direct_composition EGL_NV_post_sub_buffer EGL_KHR_create_context EGL_EXT_device_query EGL_KHR_image EGL_KHR_image_base EGL_KHR_gl_texture_2D_image EGL_KHR_gl_texture_cubemap_image EGL_KHR_gl_renderbuffer_image EGL_KHR_get_all_proc_addresses EGL_KHR_stream EGL_KHR_stream_consumer_gltexture EGL_NV_stream_consumer_gltexture_yuv EGL_ANGLE_flexible_surface_compatibility EGL_ANGLE_stream_producer_d3d_texture EGL_ANGLE_create_context_webgl_compatibility EGL_CHROMIUM_create_context_bind_generates_resource EGL_CHROMIUM_sync_control EGL_EXT_pixel_format_float EGL_KHR_surfaceless_context EGL_ANGLE_display_texture_share_group EGL_ANGLE_create_context_client_arrays EGL_ANGLE_program_cache_control EGL_ANGLE_robust_resource_initialization EGL_ANGLE_create_context_extensions_enabled EGL_EXTENSIONS(nullptr): EGL_EXT_client_extensions EGL_EXT_platform_base EGL_EXT_platform_device EGL_ANGLE_platform_angle EGL_ANGLE_platform_angle_d3d EGL_ANGLE_device_creation EGL_ANGLE_device_creation_d3d11 EGL_ANGLE_experimental_present_path EGL_KHR_client_get_all_proc_addresses EGL_ANGLE_explicit_context WebGL 2 Driver Renderer: Google Inc. -- ANGLE (NVIDIA GeForce GTX 750 Ti Direct3D11 vs_5_0 ps_5_0) WebGL 2 Driver Version: OpenGL ES 3.0 (ANGLE 2.1.0.ae3b5a6552ee) WebGL 2 Driver Extensions: GL_ANGLE_client_arrays GL_ANGLE_depth_texture GL_ANGLE_explicit_context GL_ANGLE_explicit_context_gles1 GL_ANGLE_framebuffer_blit GL_ANGLE_framebuffer_multisample GL_ANGLE_instanced_arrays GL_ANGLE_lossy_etc_decode GL_ANGLE_multiview GL_ANGLE_pack_reverse_row_order GL_ANGLE_program_cache_control GL_ANGLE_request_extension GL_ANGLE_robust_client_memory GL_ANGLE_texture_compression_dxt3 GL_ANGLE_texture_compression_dxt5 GL_ANGLE_texture_usage GL_ANGLE_translated_shader_source GL_CHROMIUM_bind_generates_resource GL_CHROMIUM_bind_uniform_location GL_CHROMIUM_color_buffer_float_rgb GL_CHROMIUM_color_buffer_float_rgba GL_CHROMIUM_copy_compressed_texture GL_CHROMIUM_copy_texture GL_CHROMIUM_sync_query GL_EXT_blend_minmax GL_EXT_color_buffer_float GL_EXT_color_buffer_half_float GL_EXT_debug_marker GL_EXT_discard_framebuffer GL_EXT_disjoint_timer_query GL_EXT_draw_buffers GL_EXT_frag_depth GL_EXT_map_buffer_range GL_EXT_occlusion_query_boolean GL_EXT_read_format_bgra GL_EXT_robustness GL_EXT_sRGB GL_EXT_shader_texture_lod GL_EXT_texture_compression_dxt1 GL_EXT_texture_compression_s3tc_srgb GL_EXT_texture_filter_anisotropic GL_EXT_texture_format_BGRA8888 GL_EXT_texture_norm16 GL_EXT_texture_rg GL_EXT_texture_storage GL_EXT_unpack_subimage GL_KHR_debug GL_KHR_robust_buffer_access_behavior GL_NV_EGL_stream_consumer_external GL_NV_fence GL_NV_pack_subimage GL_NV_pixel_buffer_object

I called for more help.

I found it! The piece of 'System Mechanic', called Powersense, will change power settings on its own recomendations of 'High' CPU usage. I went in and adjusted, (read 'shut off',) function and problem disappeared. Good Firefox!

That was very good work. Well done.