When you upgrade VMware Site Recovery Manager from version 8.5.0.2 to 8.5.0.5, you must complete all the upgrade tasks on the protected site first and then start the upgrade tasks on the recovery site.
Prerequisites
Ensure that vSphere Replication is upgraded to its latest version 8.5.0.5.
Note:
During the Site Recovery Manager upgrade, Site Recovery Manager is unavailable until you upgrade it and vSphere Replication to their latest versions 8.5.0.5.