Without a testcase I won't be able to fix this as I have not seen it. I'm thinking it is related to an issue in 1.20.0.4 that is now fixed in 1.20.0.5 regarding scale and moving Person by root node. It could cause some joints to get pretty messed up. After 1.20.0.5 is out, please see if you can replicate the issue, and if so, please send me the scene or circumstances required to repeat the issue.
Thanks