In original topology
VC1>>>PSC1
VC2>>>PSC2
Both nodes were 6.7.0 build-10244857
VC1 was converged to embedded node with no issues.
VC2 was failing with "replication-partner-hostname is not in replication with current PSC"
In the %temp%\vcsaCliInstaller-<date-time>-<id>\workflow_<id>\converge\converge_mgmt.log there are entries similar to:
YYYY-MM-DDT12:37:58.937Z INFO converge Validating Provided Configuration ...
YYYY-MM-DDT12:37:59.31Z ERROR converge Unable to run ldapsearch
YYYY-MM-DDT12:37:59.32Z ERROR converge --replication-partner-hostname is not in replication with current PSC.
YYYY-MM-DDT12:37:59.32Z ERROR converge Pre-checks failed for converge.
Running replication status we seeing that VC1 is embedded node and VC2 having external PSC.