Somewhere here in the forum there was a post about this, but I couldn’t find it anymore: the spinning icon in the login screen of SDDM shows this broken texture on 2 of my computers:
Instead of the white circle, only this squashed texture can be seen. Graphics card on the one affected computer is from AMD, on the other is an integrated AMD unit , on the unaffected computer it is an integrated AMD unit. Graphics drivers are AMDGPU in all 3 cases. I had hoped that it would be fixed after a later update, but no luck. By the way, this first occurred after updating to Plasma 6.
As I seem to remember, it was a bug in the Manjaro Breath theme for sddm, which only appeared when using Wayland, and usually on AMD graphics adapters.
The solution would be to use a different sddm theme — I recommend the default Breeze theme, and you can then still set your own wallpaper in there — and/or switch to X11.
Disclaimer: It may actually rather be a bug in the splash screen, rather than in the sddm theme, in which case I recommend disabling the splash screen altogether, because it doesn’t really do anything, other than slowing down the loading of the desktop.
Well, as I said, it doesn’t occur on one of my computers with integrated (AMD) graphics, only on the other two. The specifications are roughly the same on both, except that one computer has an RX 6650 XT and the other only has integrated graphics.
Thanks @Aragorn , at least that would be a temporary remedy. However, I will wait and see whether something happens in the future, or whether the developers don’t care … or just switch off the Manjaro splash screen completely.
I saw it only a few times (RX 580), and after the following update it was as expected. Since then I have disabled it completely, which is my preference.