Anything in the RGW log to hint at the issue?
*** Bug 1900023 has been marked as a duplicate of this bug. ***
I assume this is fixed (and verified) on 4.2, not 4.2.1.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (Important: Red Hat Ceph Storage 4.2 Security and Bug Fix update), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHSA-2021:0081