Initially setup my new TrueNAS (TheShire) to Connect, it mostly worked but did not seem to show and allow all the various options to work. I left it alone. Recently rebuilt my old TrueNAS (Mordor) as a backup replication target, added it to Connect and everything is working.
I decided to remove my Primary TrueNAS from Connect and try again. It is removed, however the primary TrueNAS still thinks it is connect. Can not seem to find a reset, can not disable the service either.
Same I use tailscale on both, however at this moment they are at home in the same subnet. Eventually the backup machine, Mordor, will end up at my in-laws.
BTW - I did see on the most recent TechTalk where the free version of TrueNAS Connect now supports 2 hosts. I am sure when I first set mine up that may not have been the case, not sure if that iimportant.