Issue with importing fillet in Showcase

I have been playing with Inventor and showcase for a while now.

I came across an error that adds additional faces to my model in showcase when I import it there.

I have attached two images.

The one I used the fillet command and it added the weird looking faces. The other I just used a normal chamfer command and it works perfectly.

Has anyone had this issue before? It's kind of hard to find the right words to search for online.

Thanks in advance! :)