User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:88.0) Gecko/20100101 Firefox/88.0

Steps to reproduce:

Go here:
https://smartslider3.com/bugs/firefox/perspective1/
and hover over the element.

Actual results:

During a "transform" CSS code created rotation, a weird skewing happens.

This seems to happen, because there are multiple parent elements with "perspective" CSS codes.

Expected results:

There shouldn't be any skewing. The same result should happen, as what happens by adding this CSS code:
*{
perspective:none!important;
}

Or you can compare to Chrome too.

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

Disabling WebRender fixes the issue on Nightly90.0a1 Windows10.

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=757f1c83278b03859f4f23e85e22e732c2bc313f&tochange=c5798de806e28251aeda7d23123ab2b05eb7e8fb

Gabor, is this issue important for your website, or just happens to be something you noticed?

We are WordPress plugin developers, so this is rather something that could be important for some of our users, not specifically to us. We were contacted by one user about this issue, and that is why this bug report was opened.