I just decided to test my iPhone connection over WiFi at my in-laws place via ZeroTier back to ZeroTier session on my windows core setup, just had to hit help in the connection screen to enter the ZeroTier IP address of the core machine and bingo all works fine. Had to add the iPhone as an endpoint tho and I disabled private. Listening now no breakups.
Dropping the WiFi and trying on 4g won’t work still, so you need a WiFi connection which is still at least something to get sound while out of the house. Maybe using a WiFi hotspot will work to another device on 4g…but that’s getting a bit too complicated