The background color of Tab bar turned white after 10/2 updating, text not visible, will return to normal when and only when website opening in new tab, will return broken after website loaded.

It only happens in the default theme.

Please check the video, https://youtu.be/RaStSkreV4c

The second video, https://youtu.be/nbKElZNkyY0

• Only resumes to normal during web loading. After page ready, it return to white.
• And it will always resume normally when system page (setting, addon... etc) is in the foreground.
• When focus to the URL bar, it seems to be much larger and the dropdown menu also seems weird.
• Turn off hardware acceleration fix tab bar background

Turn off hardware acceleration fix tab bar background, but URL teme still weird

bg color resume to normal for a short time, while loading website in a new tab (open website in current tab won't work)

• Disable all addon don't help.
• Can't represent issue in new profile. (new profile work normally)

• Work normal in safe mode
• Broken after "restart with addon disabled"

• Refresh Firefox fix issue (even normal after resume all 480 tabs)

"Enlarged location bar on focus" problem occurs on both of my Windows 10 PCs, but not the others.

(In reply to Selim Şumlu from comment #9)

"Enlarged location bar on focus" problem occurs on both of my Windows 10 PCs, but not the others.

It turns out the "megabar" (bug 1561531) is a feature that hasn't recieved much love so far, but it's not a bug.