It seems there is a networking/connectivity issue. Could you open a support case and collect SRM server logs + UI client logs (%ProgramData%\VMware\VMware vCenter Site Recovery Manager\runtime\srm-client\logs\dr.log). if you have vSphere Replication in the picture, also take /var/opt/apache-tomcat/logs/dr.log
The issue in the end was replication between PSC devices and just waiting for things to refresh after the upgrade. I rebooted the PSCs and VCSAs as well for good measure. The next day it was working as expected. Thanks for checking.