IES-Light thumbnails are broken

I am not sure if it is a bug or not, but it is driving me insane.

It works correctly when put on point lights, however thumbnails change to a gray blur after being dragged.

And yeah after being used or dragged they all meet the same fate.


I mean it is… usable? But I don’t know what am I looking at, which is a problem because I am not gonna sit through 100 ies lights to find the right one.

I tried 3 different versions:

UE 5.4.4
UE 5.3.2
UE 5.2.1

Validating IES profiles and reloading them

Nothing works

Any ideas?