Hi, I’m having a recurring UI issue in Thunderbird with the toolbar above the message preview pane. After some time of using Thunderbird, the area between the message list and the message preview becomes visually corrupted. The toolbar where the Reply / Reply All / Forward buttons should appear either disappears completely or turns into a broken/glitched gray bar. I attached a screenshot showing the problem. What I already tried: Restarting Thunderbird Starting in Troubleshoot Mode Disabling all add-ons Resetting UI/customization settings These actions help only temporarily. After some time, the issue comes back again. Additional info: Windows 11 64-bit Latest Thunderbird version The problem seems random, but happens multiple times per day It affects usability because I lose quick access to reply buttons and message actions Has anyone experienced something similar or knows what may cause this? Humanity invented email clients 50 years ago and somehow we’re still fighting disappearing buttons like it’s experimental Soviet software. Beautiful continuity of civilization. Thanks.