FBX import changed?

I’m moving from 5.4.4 to 5.5.0 using the same file. In 5.4 the file type is recognised and the appropriate dialogue appears, in 5.5 the (not sure how to describe it - top-level? Generic?) import dialogue appears. Happy to share, the file has come from the Terabilis Mixamo to Metahuman converter.
OffensiveIdle.UE.fbx (4.4 MB)