How come my armature won't import properly?

I’m trying to import a weapon model from Blender that uses an armature for animations and such, but using send2ue doesn’t work at all, it simply says “Import failed” in ue. If I export FBX manually and import, it works, however all the transforms are real messed up and I have no clue why.

If anyone wants to try to reproduce the error:
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