Have you fixed it?
It seems I have the same problem with you.
if the url have $xxx, it return BAD REQUEST, and forbidden info:
{"$diagnoses":[{"$severity":"error","$message":"Forbidden [x-9c41b01b73bb 2021-06-17T01:46:09.035Z]","$stackTrace":"Forbidden [x-9c41b01b73bb 2021-06-17T01:46:09.035Z]"}]}