Sorry if I’m posting this comment in the wrong place or something, only creeped before and never posted! (Thanks for making this post btw)
I wanted to say that I have this issue with the newest version of unreal - spent all day yesterday fidgeting with the settings in both blender and UE, no luck. I moved back down to 4.15 this morning, reset all of my export/import settings to how I usually do it, and it imported just fine.
It’s really frustrating - look forward to seeing this corrected.