Automatic thumbnail generator not working anymore

After the 0.25 update i noticed that whenever i saved a configuration of a vehicle i made, the game would make nice a thumbnail of the config i just made unlike previous versions of the game, no need to open the Thumbnail generator, the game just made really nice thumbnails like the ones on vanilla cars for any configuration that i made in any map that i wanted, which was really convenient and a nice touch.
However, the game suddenly stopped taking these thumbnails when making a configuration. I have tried many methods to get this working again, but i haven't been able to fix it, which is kinda dissapointing since they don't look as nice as they did b efore.
Is there a way to get this working again?

i'll attach some examples to demonstrate better the issue.