This morning I had a similar issue to ones that were reported a while back of current playback queue being skipped when changing networks.
I had a queue of 59 remaining tracks. I switched from my home WiFi to mobile and when the current playing track finished the ARC app showed no items playing.
I could access the queue and see the 59 skipped tracks but trying to play one of them I got the error message „unexptectedplaybackissue“.
I had to select a track not in the queue to make ARC playback music again. After that I was also able again to playback the previously queued songs.