I run into the same issue. Somhow my brand new Samsung 990 Pro failed (i guess maybe a thermal issue). After rebooting it looks good again. But it shows blue "New" device. Is the suggested fix really save and the official way?!? It feels wrong to have to remove the array! I don't want to mess things up, that's my app settings drive.
OK this does the trick:
It's also mentioned in the docs of the container:
Additional it is important to set network to host to allow LAN-sync.
As bonus i added
To the go-file to allow monitoring of all folders.
I have the excactly same effect. I just started with Unraid and this is the first thing i wanted to setup. The container even crashed one time and afterwards it got a new ID to link. But so far no files are synced at all. I need this to replace my Synology...