This TIDAL/Roon problem happened to me again yesterday, but I attributed it as possibly being related to the macOS updated I had just completed moments earlier on a Roon remote laptop (core is on a Nucleus). I posted some details about it here. Then today, about 20 minutes ago, it just happened again – not doing anything Roon related, when playback simply stopped. Went into (Roon) Settings: Services and saw the spinning icon next to my TIDAL entry. Didn’t need to logout then back into TIDAL this time, but I did have to restart the Roon Server Software via the Nucleus web interface.
It’s not that it’s a difficult problem to resolve, but it definitely is happening too frequently, and seems limited to TIDAL+Roon (no problems ever noted in my TIDAL iOS apps). Glad to read in earlier posts that this is being worked on! Time to get back to the music, and away from the troubleshooting, rebooting, etc. 