Hi njhp94, This is a known type of issue that can happen with Firefox on Windows 11 after sleep/screen saver, where the window gets reprocessed by Windows as if the usable screen area changed (even though it didn’t). That can cause Firefox to “recalculate” its window height and shrink a bit each wake cycle. A few common causes seen in similar reports are Windows display scaling changes after wake, multi-monitor or DPI reinitialization, or Firefox restoring window geometry incorrectly after a suspend/resume event. It also tends to affect Firefox more than other apps because of how it saves and restores window size internally. Things that usually help: * Check Windows display scaling (Settings → Display → Scale) and keep it consistent (100%/125% etc.) * If you use multiple monitors, try disabling “remember window locations” temporarily to test * Turn off “smooth scrolling / hardware acceleration” in Firefox (just as a test) * Update both Firefox and GPU drivers, since some fixes are graphics-related * As a workaround, maximize once after wake (which forces Firefox to recalculate correctly) There are also ongoing discussions about similar “window size changes after sleep” bugs in Firefox + Windows 11 combinations, so it’s likely not something you’re doing wrong, but a window management edge case between Firefox and the OS. If you want, I can help you narrow it down to the exact trigger on your setup (multi-monitor, scaling, etc.).