pt-table-checksum breaks MySQL replication with MariaDB 10.1.12

I have two galera clusters C1 and C2 each with two nodes. I have async replication set between node ‘C1N1’ of cluster C1 and ‘C2N1’ of cluster C2 (C1N1 —> C2N1).
The binlog format for both C1 and C2 is ROW. I have tested the replication with basic create table and insert table commands and it works as expected.

As soon as I run the pt-table-checksum command on C1N1, I see that the replication link C1N1 —> C2N1 has broken. Running the ‘show slave status\G’ command on C2N1 shows this error message: Last_SQL_Errno: 1047
Last_SQL_Error: Node has dropped from cluster
The pt-table-checksum was run with the following parameters: ./pt-table-checksum h= --user=root --password=pass123 --replicate mydb.checksums --no-check-binlog-format --ignore-databases=mysql

Any pointers please

From pt-table-checksum documentation:
"The number of possible Percona XtraDB Cluster setups is large given that it can be used with regular replication as well. Therefore, only the setups listed below are supported and known to work. Other setups, like cluster to cluster, are not support and probably don’t work.
So, to me checksuming between cluster nodes is not supported although I never tested it.