RHCS during upgrade RHCS 4 -> RHCS 5 ceph-mon is failing with "FAILED ceph_assert(fs->mds_map.compat.compare(compat) == 0)"

Issue

After upgrade of the first ceph-mon to RHCS 5 version, not upgraded ceph-mon is failing with:

  debug     -1> 2023-06-20 11:26:50.431 7f0a57e0c700 -1 /builddir/build/BUILD/ceph-14.2.22/src/mds/FSMap.cc: In function 'void FSMap::sanity() const' thread 7f0a5
7e0c700 time 2023-06-20 11:26:50.429250
  /builddir/build/BUILD/ceph-14.2.22/src/mds/FSMap.cc: 766: FAILED ceph_assert(fs->mds_map.compat.compare(compat) == 0)

   ceph version 14.2.22-128.el8cp (40a2bf9c4e79e39754d69a95cd51bd60991284be) nautilus (stable)
   1: (ceph::__ceph_assert_fail(char const*, char const*, int, char const*)+0x156) [0x7f0a67933d4c]
   2: (()+0x275f66) [0x7f0a67933f66]
   3: (FSMap::sanity() const+0xd0) [0x7f0a67e96c50]
   4: (MDSMonitor::update_from_paxos(bool*)+0x43c) [0x5626ee53ba7c]
   5: (PaxosService::refresh(bool*)+0x10e) [0x5626ee47325e]
   6: (Monitor::refresh_from_paxos(bool*)+0x1ac) [0x5626ee338b1c]
   7: (Paxos::do_refresh()+0x57) [0x5626ee461527]
   8: (Paxos::handle_commit(boost::intrusive_ptr<MonOpRequest>)+0x309) [0x5626ee467139]
   9: (Paxos::dispatch(boost::intrusive_ptr<MonOpRequest>)+0x457) [0x5626ee46d307]
   10: (Monitor::dispatch_op(boost::intrusive_ptr<MonOpRequest>)+0x13b7) [0x5626ee36ee47]
   11: (Monitor::_ms_dispatch(Message*)+0xa98) [0x5626ee36fd18]
   12: (Monitor::ms_dispatch(Message*)+0x2a) [0x5626ee3a33aa]
   13: (Dispatcher::ms_dispatch2(boost::intrusive_ptr<Message> const&)+0x2a) [0x5626ee39fbca]
   14: (DispatchQueue::entry()+0x134a) [0x7f0a67b8fb5a]
   15: (DispatchQueue::DispatchThread::entry()+0x11) [0x7f0a67c46491]
   16: (()+0x81cf) [0x7f0a6461f1cf]
   17: (clone()+0x43) [0x7f0a6328add3]