Our cluster is using hostname failover.
Half the cluster is only showing a single protocol in protocols & templates, even though they are present on all present and working on all DMA's.
Also the BPA page wasn't displaying anything without carrying out two reboots of the entire cluster.
The ClusterEndpoints.json is configured correctly (after previous manual intervention being on hostname failover), and all the other config changes look correct as documented on Migrating to BrokerGateway and I've run NATSRepair.exe as a double check.
So if I understand this correctly, these problems started after the entire cluster was migrated to BrokerGateway managed NATS?
At first glance those issues sound unrelated to NATS as NATS does not affect the UI. Protocols not loading in would result in all elements being in error, and I take it this is not the case here?
As a last resort you could try to migrate back to the old version of NATS. The procedure is identical with the dmupgrade package from Dojo.
Rolling back to the old version of NATS resolved Protocols & Templates showing all the protocols again, but the PBA page not populating needed a second reboot again to get them to display