Sorry, I forgot to mention, that it is the case if 3 mouse button emulation is turned on.

If I open the attached test1.blend in Blender 2.8 3d8cbb534f82, the plane is pink. If you select the only texture slot or you switch from lookdev to anything else it gets black as intended. If you do nothing, you can still paint (changes appear in the image editor window) but the plane is still pink.

The linked materials were{F6239619} missed. Sorry.

Should be something with the overlays, as if they are turned off, project saved, the object is fine when reloaded.

Ok, you are right. Should I do the 3 extra reports and point this for the first one or should I leave it now as it is?
According to the 4th issue, that is a bug, no question: it feeds unusable data into a list (you can select textures for painting, that actually can't be edited at all, as they are linked). If you still think it can be useful for later feature, a filter would be a solution.

Thank you guys!