Hey, good you’ve sorted the other issue out.
Not too sure, I’m not an expert with animation and only know the workflow I’ve used with my characters using 3ds max… Also haven’t tried retargeting before…
You could try a few things I guess to track it down… Could be something to do with the retargeting process or possibly something to do with the original rigging…? Did you retarget using the same skeleton or retarget the character to a different skeleton? Did you have to retarget the character? Was the character rigged and animated before retargeting and if so was the problem visible before?