OK, this was an interesting one….
I was testing some kit so decided to leave Roon playing continually for a couple of days.
On the first morning I selected either ‘play all’ from the albums page, or ‘play’ from a genre page (can’t remember which). There was way more than enough material to cover the day, but by the evening the system had stopped. When I went to genres, many of them had disappeared - on the first night only four genres remained.
I repeated the process on morning day 2, playing ‘all albums’ this time due to lack of genres, but it had stopped by the evening again. I was now down to only a single genre (spoken word), and all tidal albums had disappeared.
I restarted the iPad app but it made no difference. I then restarted roonServer and all was well.
Just an FYI - it looks like somethings not quite right there?