And again at ~12:20 BST (20th August). Restarting has again fixed the problem. I also tried restarting the Nest Mini this time, but that didn’t help.
I’m currently using an SSH client on my phone (https://connectbot.org/) to make restarts easier, and will have a look at scheduling a cron job on my Mac Mini to do nightly Roon restart. The script I’m using is:
killall Roon
killall RoonServer
open /Applications/Roon.app
I really hope this is highlighting how useful it would be to have a restart button within the Roon client itself. The thread here has been discussing the possibility since 2015!