I also noticed it was the same 21.5.x and kinda hoped it may be fixed with 21.6.x.
I reverted back to 21.2.x that works and won't be updating until fixed.
Luckily (or not) I don't have any of the FSR enabled titles so no real reason to update just yet.
Do hope it is fixed though.
I have been dealing with the same issues. The XPlane Devs have a issue in their Bug Database. I am fairly confident they would be very happy to help any AMD Devs who need more info on the issue.
XPD-10709, XPD-10868 Plugin OpenGL drawing artifacts under Windows with Vulkan on AMD GPUs.
Just updated to 21.7.1, bug is still here. Please do something with it)
As i now, this glith only appears on polaris and under amd cards.
Thanks for letting us know that it is still not fixed.
Also good to see that it may not be an issue for those on Navi cards (doesn't help me with my RX480)