I’ve tried OBJ export without such errors as you have:
The model in RealityCapture and Unreal Engine is basically the same.
I used ordinary export settings:
and during import the model I haven’t changed any of them.
I used the datasets from this CLI sample script: RealityCapture CLI Sample Scripts - Capturing Reality
Also, I mentioned the other viewer not to solve the issue, but to check, if the problem is also in other applications.
Which version of RealityCapture are you using?