Specific model shape will break all other models

So I got back onto fiddling with Mcreator now that 1.14.4 support is out and after making a lot of elements I tried implementing this model:

https://i.imgur.com/VhzEUiK.png

https://i.imgur.com/dcfwes0.png

And once I imported the model and made a mob with it, it and all the other mobs I had so far added turned into white boxes the size of their respective entity bounding box in the test environment.

https://i.imgur.com/SnN0YQv.png

Once I removed the entity that used this model and opened the test environment again, the other models worked fine again. I would attempt this multiple times and occasionally one of the other entities might be spared from being turned into white boxes if they were lucky. I tested different configurations for the entity and it all resulted in the same result, I never had any errors or anything occur, either. I also tried importing the model without animations, didn't do anything.

I also tried importing some other model, and no other model had this phenomenon occur, so I figured maybe the .java file of the model or it's .tcn is somehow corrupted so I decided to fully remake the model from scratch. Same proportions but new texture, completely new file, no shared names anywhere. But it somehow ended up doing it again.

I'm really at the end of my wit how this issue can occur on the very specific shape of the model, rather than the file itself.