I filed a bug some while ago , but so far no reaction yet:
https://bugs.freedesktop.org/show_bug.cgi?id=104549
I inlucded an apitrace so developers can "replay" opengl commands and debug what is going wrong.
Incidentely I retested sh3 on my intel integrated graphics , no artefacts there exactly as I remember

, so should be an AMDGPU issue , even replaying the trace on intel looks ok too.