I think the issue was due to the theme in the extension settings. I reverted to the system auto theme. We'll see how it goes. I was previously using Dark Space. We'll see how it goes with the regular Mozilla system theme. Just in case, I also disabled hardware acceleration.

Unfortunately, the problem persists—the tab list within a group doesn't expand when hovering over it. This is likely due to a GUI issue, as hardware acceleration was disabled. Name: Firefox Version: 150.0 Build ID: 20260415192539 Distribution ID: Update Channel: release User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:150.0) Gecko/20100101 Firefox/150.0 OS: Windows_NT 10.0 26200 Launcher Process: Enabled Multi-Process Windows: 1/1 Fission Windows: 1/1 Enabled by Default Remote Processes: 21 Enterprise Policies: Disabled Google Location Services Key: Found Google Safebrowsing Key: Found Mozilla Location Services Key: Found Safe Mode: false Memory (RAM): 31.7 GB Available storage space: 234 GB Manipulators: Mouse 1-Callout Contextual Chatbot Suggestion Treatment A Rollout V2: (treatment-a-tab-switching-copy) AI Chatbot Page Summarization MVP - treatment-a-callout-badge Rollout V4: (treatment-a-callout-badge) BackgroundUpdate: Enable unelevated installations (Rollout) -- 3-release: (enabled) Client Side Sampling of Performance Metrics: (control) Context rotation ID every 3 days: (control) Desktop Credit Card Autofill Global Enablement Rollout (Release): (creditcard-enable) Disable legacy spoc ping by default: (control) Disable legacy top-sites ping by default: (control) Downsample uptake.remotecontent events glean feature: (control) DTLS 1.2 rollout (rollback?) for webrtc - control Rollout: (control) Enable Enrollment Status Telemetry for Firefox Desktop (via nimbusTelemetry): (control) Enable Nimbus Unenrollment Synchronization: (control) Enable OHTTP for MARS communications on Release: (control) Limit use of OCSP - Rollout: (enforce) Fast UDP for Firefox - Treatment Fast UDP Release Rollout: (treatment-fast-udp) Firefox Backup feature gradual rollout: (treatment) Fox Doodle Multi-Action CTA 2025 - Dummy Rollout V2: (treatment-a) Fx Accounts Ping (release rollout 2): (control) Multiple Profile Switching Rollout Feature only: (treatment-a-multi-profiles) Multiple Profile Switching Rollout Messages only: (treatment-a-multi-profiles) New Tab 151.2.20260328.211913 to Release 149: (rollout) New Tab content ping (rest of world rollout): (treatment) PDF Annotations Signatures - Treatment A - Already Default Rollout: (treatment-a) Pin Frequently Used Websites - Promo Rollout, Day 3+ users, All Locales: (rollout-branch) Private Window Visual Refresh - rollout: (control) Relay integration into Firefox 118+ Release for all FXA and autofill users: (enable-relay-integration) Set to Default - Hamburger Menu Rollout: (treatment-c) Smart shortcuts v3-lr2 - no-lr Rollout: (no-lr) Tab Notes - Firefox Labs 149: (control) TOU Experience 2 - Rollout V2: (treatment-a) Unified API for spocs and top sites - controlled rollout for release 133+: (control) Vertical tabs Promo Rollout - Day 3 Profiles, All Locales: (treatment-a) Visual Search Rollout: (google-lens-rollout) Remote Processes ------------------ Type: RDD Quantity: 1 Type: Sandboxed Web Content Quantity: 9 Type: Extension Quantity: 1 Type: Reserved Quantity: 3 Type: GPU Quantity: 1 Type: Socket Quantity: 1 Type: Privileged About Page Quantity: 1 Type: Media Foundation Engine Utility Quantity: 1 Type: Windows Media Foundation Utility Quantity: 1 Type: Oracle JavaScript Utility Quantity: 1 Type: Universal Audio Decoder Utility Quantity: 1 Add-ons ---------- Name: English (US) Dictionary Type: dictionary Version: 144.20250826 Enabled: true Location: app-profile ID: en-US-mozilla@dictionaries.addons.mozilla.org Name: Add-ons Search Detection Type: extension Version: 3.0.0 Enabled: true Location: app-builtin-addons ID: addons-search-detection@mozilla.com Name: Dark Reader Type: extension Version: 4.9.124 Enabled: true Location: app-profile ID: addon@darkreader.org Name: Data Leak Blocker Type: extension Version: 144.0.0 Enabled: true Location: app-builtin-addons ID: data-leak-blocker@mozilla.com Name: Form Autofill Type: extension Version: 1.0.1 Enabled: true Location: app-builtin-addons ID: formautofill@mozilla.org Name: IPP Activator Type: extension Version: 0.1 Enabled: true Location: app-builtin-addons ID: ipp-activator@mozilla.com Name: New Tab Type: extension Version: 151.2.20260328.211913 Enabled: true Location: app-profile ID: newtab@mozilla.org Name: Picture-In-Picture Type: extension Version: 1.0.0 Enabled: true Location: app-builtin-addons ID: pictureinpicture@mozilla.org Name: Red Shield VPN Type: extension Version: 300.0.22 Enabled: true Location: app-profile ID: {06d09a41-7ecd-429e-a6fa-87b0d1b2d5cc} Name: uBlock Origin Type: extension Version: 1.70.0 Enabled: true Location: app-profile ID: uBlock0@raymondhill.net Name: Web Compatibility Interventions Type: extension Version: 151.3.20260409.134825 Enabled: true Location: app-system-addons ID: webcompat@mozilla.org Name: Language: English (US) Type: locale Version: 150.0.20260415.192539 Enabled: true Location: app-profile ID: langpack-en-US@firefox.mozilla.org Name: System Theme - Auto Type: theme Version: 1.4.2 Enabled eno: true Location: app-builtin ID: default-theme@mozilla.org Name: AdBlocker Ultimate Type: extension Version: 3.8.48 Enabled: false Location: app-profile ID: adblockultimate@adblockultimate.net Name: AdGuard Anti-Banner Type: extension Version: 5.3.1.7 Enabled: false Location: app-profile ID: adguardadblocker@adguard.com Name: AutoPinTab Type: extension Version: 1.3.5.1 Enabled: false Location: app-profile ID: autopintab__coolsoft.ita@gmail.com Name: ReYohoho Twitch Proxy 1080p/1440p (Russia) Type: extension Version: 2.3.0 Enabled: false Location: app-profile ID: reyohoho-twitch-proxy2@rhhhhhhh.live Name: Light Type: theme Version: 1.3.4 Enabled: false Location: app-builtin ID: firefox-compact-light@mozilla.org Name: Dark Type: theme Version: 1.3.4 Enabled: false Location: app-builtin ID: firefox-compact-dark@mozilla.org Name: Colorful Abstract Neon Type: theme Version: 2.0 Enabled: false Location: app-profile ID: {9fd56529-f621-4820-8128-f0bbbdbd8a73} Name: Cosmic Cloud Type: theme Version: 2.0 Enabled: false Location: app-profile ID: {cdabc232-3126-426f-8624-3d4b1609e431} Name: Dark space - The best dynamic theme Type: theme Version: 1.1.2 Enabled: false Location: app-profile ID: {22b0eca1-8c02-4c0d-a5d7-6604ddd9836e} Name: Firefox Alpenglow Type: theme Version: 1.5.2 Enabled: false Location: app-builtin ID: firefox-alpenglow@mozilla.org Name: Moss Type: theme Version: 1.1 Included: false Location: app-profile ID: {f9261f02-c03c-4352-92ee-78dd8b41ca98} Name: Ocean Type: theme Version: 1.1 Enabled: false Location: app-profile ID: {750fa518-b61f-4068-9974-330dcf45442f} Name: Splatoon 2 Colors [Theme] Type: theme Version: 1.0 Enabled: false Location: app-profile ID: {d6eb3386-e265-4e53-8cee-6c63097ce382} Name: Terracotta Type: theme Version: 1.1 Enabled: false Location: app-profile ID: {25b5a343-4238-4bae-b1f9-93a33f258167} Type: Windows Firewall Active: false Style Sheets: No style sheets found Graphics ------- Capabilities Device Window Pixel Ratio: 1 Compositing: WebRender (Software) Font Visibility Debug Info: Windows Platform Asynchronous Pan/Zoom: Wheel input enabled; Scrollbar dragging enabled; Keyboard enabled; Autoscroll enabled; Smooth gesture zoom enabled WebGL 1 - WSI Driver Info: outOfProcess: false; inProcess: true; EGL_VENDOR: Google Inc. 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