So after getting Krita 5.0 installed, I ran into an issue right away when opening a document. When opening a document it looks messed up almost like a tearing effect.
Here are two images to show what it looks like.
This is a known issue with 16-bit integer images on macOS.
Current workaround is to disable “Use texture buffer” in the display settings (canvas acceleration tab).
Alternatively, you can keep “Use texture buffer” active (it makes lines much smoother on MacOS), but just avoid using “RGBA 16-bit integer” color spaces. Use “RGBA 8-bit integer” or “RGBA 16-bit floating point” ones. This bug is specific to M1 macs only.