Microsoft iSCSI target server 2016 failover cluster doesn't work in Server Manager after transfering roles
Solution 1:
I see similar issue posted on technet. Is there any chance to see what does Event Log show?
For the case, from my experience, Microsoft iSCSI target is too slow. Currently, I use StarWind Virtual SAN Free that delivers really fast iSCSI server with the additional functionality of cache and log-structured file system (snapshots, dedupe, etc.). I suggest you try it since it solves the problem having a single management console: iSCSI server can be installed on whatever host you will to run it and then you can manage the server from any host at all using web GUI. StarWind Virtual SAN allows using PowerShell as well if you want to.