Cool, just review the StarWind Interfaces in the config files and update them accordingly. Update iSCSI Initiator too (and purge the favorite targets).
To bring CSV1 online, stop StarWindService on one node > mark the CSV as synchronized on the remaining node, and check the data. If all is good, start the node and start replication manually.
See if there is volume on the underlying storage of that node. If all is good with the networks, the easiest will be removing that volume from the configs. Stop the service > go to StarWind.cfg > Remove any entry for that volume (target and files) > Remove entries in /headers and underlying storage > run the remove partner script against the "healthy" node. That should remove the devices. Add the replication partner afterward. Afterward, make sure that the priorities logic will persist
viewtopic.php?t=5731.
It looks like CSV1 does not want to replicate. Check networking and make sure the files are there, please.
P.s. I'd really suggest reviewing the system with the tech, as it will get a support plan. It will be much faster to handle this situation during the call.