And I also see the Unexpected error in broker-rsp-ceph-radosgw-5:

ubuntu@hevelius:~$ juju debug-log -i ceph-radosgw/5 --replay | grep -i "Request already sent"
unit-ceph-radosgw-5: 17:26:56 DEBUG unit.ceph-radosgw/5.juju-log mon:65: Request already sent but not complete, not sending new request

ubuntu@hevelius:~$ juju run --unit ceph-radosgw/5 'relation-get -r mon:65 - ceph-mon/0'
auth: cephx
ceph-public-address: 10.0.3.24
egress-subnets: 192.168.210.135/32
fsid: 4e0ece9e-a1d5-11ea-8976-00163e2267d7
ingress-address: 192.168.210.135
private-address: 192.168.210.135
radosgw_key: AQB6GNVelHpAJRAAGFQJyxi1hpOnaeuMdstXgQ==
rgw.juju-10aa60-3-lxd-5_key: AQAEOtVe1YbsDBAAqQHMZNpZUUZ+QJFDgaEyJQ==

ubuntu@hevelius:~$ juju run --unit ceph-radosgw/5 'relation-get -r mon:65 - ceph-mon/1'
auth: cephx
ceph-public-address: 10.0.3.25
egress-subnets: 192.168.210.137/32
fsid: 4e0ece9e-a1d5-11ea-8976-00163e2267d7
ingress-address: 192.168.210.137
private-address: 192.168.210.137
radosgw_key: AQB6GNVelHpAJRAAGFQJyxi1hpOnaeuMdstXgQ==
rgw.juju-10aa60-3-lxd-5_key: AQAEOtVe1YbsDBAAqQHMZNpZUUZ+QJFDgaEyJQ==

ubuntu@hevelius:~$ juju run --unit ceph-radosgw/5 'relation-get -r mon:65 - ceph-mon/2'
auth: cephx
broker-rsp-ceph-radosgw-5: '{"exit-code": 1, "stderr": "Unexpected error occurred
  while processing requests: {''api-version'': 1, ''ops'': [{''op'': ''create-pool'',
  ''name'': ''default.rgw.buckets.data'', ''replicas'': 3, ''pg_num'': None, ''weight'':
  20, ''group'': ''objects'', ''group-namespace'': None, ''app-name'': ''rgw'', ''max-bytes'':
  None, ''max-objects'': None}, {''op'': ''create-pool'', ''name'': ''default.rgw.control'',
  ''replicas'': 3, ''pg_num'': None, ''weight'': 0.1, ''group'': ''objects'', ''group-namespace'':
  None, ''app-name'': ''rgw'', ''max-bytes'': None, ''max-objects'': None}, {''op'':
  ''create-pool'', ''name'': ''default.rgw.data.root'', ''replicas'': 3, ''pg_num'':
  None, ''weight'': 0.1, ''group'': ''objects'', ''group-namespace'': None, ''app-name'':
  ''rgw'', ''max-bytes'': None, ''max-objects'': None}, {''op'': ''create-pool'',
  ''name'': ''default.rgw.gc'', ''replicas'': 3, ''pg_num'': None, ''weight'': 0.1,
  ''group'': ''objects'', ''group-namespace'': None, ''app-name'': ''rgw'', ''max-bytes'':
  None, ''max-objects'': None}, {''op'': ''create-pool'', ''name'': ''default.rgw.log'',
  ''replicas'': 3, ''pg_num'': None, ''weight'': 0.1, ''group'': ''objects'', ''group-namespace'':
  None, ''app-name'': ''rgw'', ''max-bytes'': None, ''max-objects'': None}, {''op'':
  ''create-pool'', ''name'': ''default.rgw.intent-log'', ''replicas'': 3, ''pg_num'':
  None, ''weight'': 0.1, ''group'': ''objects'', ''group-namespace'': None, ''app-name'':
  ''rgw'', ''max-bytes'': None, ''max-objects'': None}, {''op'': ''create-pool'',
  ''name'': ''default.rgw.meta'', ''replicas'': 3, ''pg_num'': None, ''weight'': 0.1,
  ''group'': ''objects'', ''group-namespace'': None, ''app-name'': ''rgw'', ''max-bytes'':
  None, ''max-objects'': None}, {''op'': ''create-pool'', ''name'': ''default.rgw.usage'',
  ''replicas'': 3, ''pg_num'': None, ''weight'': 0.1, ''group'': ''objects'', ''group-namespace'':
  None, ''app-name'': ''rgw'', ''max-bytes'': None, ''max-objects'': None}, {''op'':
  ''create-pool'', ''name'': ''default.rgw.users.keys'', ''replicas'': 3, ''pg_num'':
  None, ''weight'': 0.1, ''group'': ''objects'', ''group-namespace'': None, ''app-name'':
  ''rgw'', ''max-bytes'': None, ''max-objects'': None}, {''op'': ''create-pool'',
  ''name'': ''default.rgw.users.email'', ''replicas'': 3, ''pg_num'': None, ''weight'':
  0.1, ''group'': ''objects'', ''group-namespace'': None, ''app-name'': ''rgw'', ''max-bytes'':
  None, ''max-objects'': None}, {''op'': ''create-pool'', ''name'': ''default.rgw.users.swift'',
  ''replicas'': 3, ''pg_num'': None, ''weight'': 0.1, ''group'': ''objects'', ''group-namespace'':
  None, ''app-name'': ''rgw'', ''max-bytes'': None, ''max-objects'': None}, {''op'':
  ''create-pool'', ''name'': ''default.rgw.users.uid'', ''replicas'': 3, ''pg_num'':
  None, ''weight'': 0.1, ''group'': ''objects'', ''group-namespace'': None, ''app-name'':
  ''rgw'', ''max-bytes'': None, ''max-objects'': None}, {''op'': ''create-pool'',
  ''name'': ''default.rgw.buckets.extra'', ''replicas'': 3, ''pg_num'': None, ''weight'':
  1.0, ''group'': ''objects'', ''group-namespace'': None, ''app-name'': ''rgw'', ''max-bytes'':
  None, ''max-objects'': None}, {''op'': ''create-pool'', ''name'': ''default.rgw.buckets.index'',
  ''replicas'': 3, ''pg_num'': None, ''weight'': 3.0, ''group'': ''objects'', ''group-namespace'':
  None, ''app-name'': ''rgw'', ''max-bytes'': None, ''max-objects'': None}, {''op'':
  ''create-pool'', ''name'': ''.rgw.root'', ''replicas'': 3, ''pg_num'': None, ''weight'':
  0.1, ''group'': ''objects'', ''group-namespace'': None, ''app-name'': ''rgw'', ''max-bytes'':
  None, ''max-objects'': None}], ''request-id'': ''d792628a-a42c-11ea-94c6-00163efd72ee''}"}'
ceph-public-address: 10.0.3.21
egress-subnets: 192.168.210.126/32
fsid: 4e0ece9e-a1d5-11ea-8976-00163e2267d7
ingress-address: 192.168.210.126
private-address: 192.168.210.126
radosgw_key: AQB6GNVelHpAJRAAGFQJyxi1hpOnaeuMdstXgQ==
rgw.juju-10aa60-3-lxd-5_key: AQAEOtVe1YbsDBAAqQHMZNpZUUZ+QJFDgaEyJQ==