After upgrading to vSphere Replication 9.0, the Configure Replication Dialogue box only shows Legacy replication as an option:
In previous versions of vSphere Replication it was recommended to disable scale-out-mode due to a known issue and the option to disable the embedded HBR server was available. These configuration changes have been seen to persist through an upgrade.
Re-balancing replications between Hbrsrvuws In this KB we recommended disabling scale-out-mode due to a legacy replication load balancing issue.
This issue does not apply with enhanced replication as the replication jobs are load balanced on the target ESXi hosts.
vSphere Replication 8.8 documentation in this document we discussed the disabling of the embedded HBR
The embedded HBR server is a critical requirement for enhanced replication to work.
In order to fix this issue you need to change some settings on the vSphere replication appliance.
/opt/vmware/hms/bin/hms-configtool -cmd reconfig -property hms-embedded-hbr=true
/opt/vmware/hms/bin/hms-configtool -cmd reconfig -property scale-out-mode=true
service hms restart