Dell Unity: Replication mode changes from sync to async after code upgrade to 5.2 (Dell Correctable)

After code upgrade to 5.2 the following issues may be seen:
Sync replication sessions will not resume.

Replication connections on Source will be showing status "Updated Needed."

The connection type gets changed from sync to async as shown below from uemcli output:
 

uemcli -d <IP> -u service -p <password> /remote/sys show -detail

2:    ID                           = RS_1  <<< RS stands for Remote System. Usually RS_0 is the local system, RS_1 is the first remote system that configures on the local Unity and RS_2 is the second Remote System. 
      Name                         = XXX-Unity
      Address                      = 10.xxx.xxx.xxx
      Alternate Management Address = 10.xxx.xxx.xxx
      Model                        = Unity 480F
      Serial number                = CKM00XXXXXXXXX
      Connection type              = async  <<<<<<<<<<<< the mode was sync before code upgrade
      Source interfaces            = 10.xxx.xxx.xxx, 10.xxx.xxx.xxx
      Local interfaces             = 10.xxx.xxx.xxx, 10.xxx.xxx.xxx
      Remote interfaces            = 10.xxx.xxx.xxx, 10.xxx.xxx.xxx
      Operational status           = Update Needed (0x8406)
      Health state                 = Minor failure (15)
      Health details               = "Update the remote system connection to pick up the latest interface changes on the local and remote systems. (https://10.xxx.xxx.xxx/help/webhelp/en_US/index.html?#unity_t_configure_replication_connections.html)"
      Synchronous FC ports         = spb_iom_1_fc0, spa_iom_1_fc0
      Bandwidth schedules          = uses available bandwidth
      Current bandwidth            = uses available bandwidth

If customer tries to 'validate and update' the connection, the operation fails with error "No remote interfaces received from the remote system".

EMCsystemlog:

"2022-06-15T22:56:51.960Z" "XXX-Unity_spa@CKM00XXXXXXXXX" "Neo_CEM" "26592" "local/admin" "ERROR" "14:610012" :: "User local/admin failed to validate remote system connections RS_1." :: Category=Audit Component=ReplicationPlugin TimeZone=UTC

cemtracer_dataprotection.log: 
15 Jun 2022 22:56:51  - [DataProtectionStorageModel] INFO - {0:271532:843299283}[26592|30974|d53ffb40][refreshLocalExternalSystemInterconnects @ ../../../components/providers/osls/common/DataProtection/StorageModel/impl/StorageResourceSubsystemImpl.cpp:1315] Updating remote system name to: XXX-Unity
15 Jun 2022 22:56:51  - [DataProtectionStorageModel] ERROR - {0:271533:341483364}[26592|30974|d53ffb40][refreshLocalExternalSystemInterconnects @ ../../../components/providers/osls/common/DataProtection/StorageModel/impl/StorageResourceSubsystemImpl.cpp:1334] No remote interfaces recieved from the remote system
15 Jun 2022 22:56:51  - [DataProtectionStorageModel] ERROR - {0:271533:343407806}[26592|30974|d53ffb40][refreshLocalExternalSystemInterconnects @ ../../../components/providers/osls/common/DataProtection/StorageModel/impl/StorageResourceSubsystemImpl.cpp:1425] Caught exception: StorageModel exception [105906509]: Failed to get the list of interfaces from the remote system.

Resolution:
The fix is available in OS 5.2.1.0.5.013 (5.2 SP1)

Workaround:
Workaround for replication connection type mismatch issue between two sides after upgraded to 5.2.
 
a. For replication connection with 'sync' type (Mismatch of site A is 'async' and site B is 'sync')
1> Change 'sync' type to 'both' from site B. (Now two sites are 'both' type)
2> Change 'both' type to 'sync' from site B (or site A).

b. For replication connection with 'both' type (Mismatch of site A is 'async' and site B is 'both')
1> Change 'both' type to 'async' from site B. (Now two sites are 'async' type)
2> Change 'async' type to 'both' from site B (or site A).


Note:
Below uemcli commands can be used to change the connection type to both or sync. The RS_x in -id field is the id of the remote system that having issue. 

Change to both: 

uemcli -u admin -p XXXXXX /remote/sys  -id RS_1 set -connectionType both 

Change to sync:

uemcli -u admin -p XXXXXX /remote/sys  -id RS_1 set -connectionType sync

 
Command syntax: 
 

  [Set]
  /remote/sys -id <value> set [ -addr <value> ] [ -dstUsername <value> { -dstPassword <value> | -dstPasswordSecure } ] [ -connectionType { sync | async | both } ] [ -bandwidthSchedules <value> ]

- Once the mode on both ends is changed to sync, please validate the connection on both ends one at a time.