User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:61.0) Gecko/20100101 Firefox/61.0 Build ID: 20180406103336 Steps to reproduce: Visit https://twitter.com/twitter and scroll down the time line. Watch the rounded avatars. Actual results: As the page is scrolled, they sometimes become squares. Expected results: With WebRender disabled this does not happen. The images remain circular.

Another example: https://www.engadget.com/

https://outlook.live.com/ not sure if this is the same issue

(In reply to hujq from comment #0) > Visit https://twitter.com/twitter and scroll down the time line. Watch the rounded avatars. WFM on Debian Testing (KDE, Radeon RX480, 2560x1440).

Windows?

I couldn't reproduce on Windows on the same machine so it seems to be Mac only.

(In reply to hujq from comment #7) > I couldn't reproduce on Windows on the same machine so it seems to be Mac only. Are you able to reproduce bug 1423087 (gfx.webrender.all=true, https://jsfiddle.net/c5wtc4sc/)? If yes, we could mark this a duplicate of bug 1423087.

(In reply to Jan Andre Ikenmeyer [:darkspirit] from comment #8) > (In reply to hujq from comment #7) > > I couldn't reproduce on Windows on the same machine so it seems to be Mac only. > > Are you able to reproduce bug 1423087 (gfx.webrender.all=true, > https://jsfiddle.net/c5wtc4sc/)? If yes, we could mark this a duplicate of > bug 1423087. Yes, I can reproduce bug 1423087 here. This is Intel Iris 6100 too.

Thanks for checking! :)