https://bugs.freedesktop.org/show_bug.cgi?id=106175
--- Comment #88 from tempel.julian@gmail.com --- Well, there's no compositor to blame, as the issue also occurs with just TearFree enabled without any compositor. Then you just have to avoid moving another window on top of the browser window, as there are no independent window layers without compositor. But yes, there are red spikes of the "inter-frame (green/red) right scale" with amdgpu.dc=1, while there are non with amdgpu.dc=0 (TearFree however doesn't work well in general without amdgpu.dc=1). I can also reproduce the issue with mpv playing a video, instead of a webrowser. It stutters the same when doing the "clicky window moving" described above.
Attaching recent dmesg and xorg log.