User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:89.0) Gecko/20100101 Firefox/89.0

Steps to reproduce:

Open Firefox Proton on Windows 7

Actual results:

The effect that blurs the object behind the title/tab bar is in front the title bar buttons, making them hard to see.

Expected results:

The blur effect is behind or does not affect the title bar buttons.

The Bugbug bot thinks this bug should belong to the 'Firefox::Tabbed Browser' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Hello!
I have managed to reproduce the issue on Windows 7 x32 with firefox 89.0. However on firefox 90.0b5 and 91.0a1 (2021-06-10) this issue doesn't occur using the default firefox theme alongside a generic theme from the os itself.

Marking this issue as NEW in order to get our developers involved and give a solution to this issue. Leaving the component as it is, if it's not the right component please feel free to change it to an appropriate one.

Thank you!

Resolving this bug as WONTFIX because Firefox versions >= 116 no longer support Windows versions < 10.