Worked with customer that had this issue and I was able to reproduce that problem.
On a 4PM combo system meaning no UMs, the system replication was failing. This means that the PM nodes that should be setup as slaves wasnt getting setup after install

Ran the following command which should have it again failed

mcsadmin> enablemysqlrep
enablemysqlreplication Thu Mar 5 20:11:59 2020

MariaDB ColumnStore Replication Feature is already enabled
Do you want to proceed: (y or n) [n]: y

Enter the 'User' Password or 'ssh' if configured with ssh-keys
Please enter: ssh

• • • • enableRep Failed : API Failure return in enableMySQLRep API

[root@ip-172-30-0-155 columnstore]# cat err.log
Mar 5 20:13:07 ip-172-30-0-155 ProcessManager[12322]: 07.435887 |0|0|0| E 17 CAL0000: line: 6911 sendMsgProcMon: ProcMon Msg timeout on module pm1
Mar 5 20:13:07 ip-172-30-0-155 ProcessManager[12322]: 07.436011 |0|0|0| E 17 CAL0000: line: 11262 setMySQLReplication: ERROR: Error getting MySQL Replication Master Information
[root@ip-172-30-0-155 columnstore]#

Just for a reference, I have had this command work for me on 1.2.5 systems that had 2 UMs. So dont know if its related to the system setup, all PMs or the number of total nodes that need to be setup as slaves.