UDIM issue - unreal getting confused with textures placing them on wrong materials

Hi guys
Have you ever encountered a situation when unreal is placing some of the textures on the wrong models / wrong materials for no reason?

Happens only with UDIMS.

Exiting the project and entering again causing unreal to switch the confusion to a different one, and placing wrong materials / models in different variations

Also when opening an image file it is opening a different one while showing the correct name.

UDIMS imported correctly with a good naming convention, using the unreal docs to verify that
The Materials and their textures have completely different names of course, so that is not the problem I guess.

Does someone know what might make that happen?