Sorry I incorrectly took it as SRM, apologies.
I don't have a huge amount of experience with vSphere Replication, so don't treat this as a definitive solution, more somewhere to look as part of your investigations. If you have used the SSO administrator credentials to connect vSphere Rep to the PSC, it will need to be reconnected now you have changed them.
I don't have vSphere Replication running in anywhere at the minute, but perhaps this may help, its based on version 8.3.
In the vSphere Replication user interface, from the list of target sites, select the connection that indicates the Not connected status. Click the Reconnect button. The Reconnect wizard starts. Enter the PSC address and the credentials of a user that has the VRM remote.Manage VRM privilege assigned, and click Next.
The article can be found here if you need to check for another version.
If i get sometime, i'll fire up an instance of it to see if i can help further, but hopefully someone with more experience will be able to assist you in the meantime.
Hope that helps.