Would be very thankful for any tips!
Best answer by Keith N
Hey there, aronluthman. If this is happening with one speaker, it seems like the speaker is having a hard time maintain a strong connection to the network compared to the other Sonos speakers. While some playback can work (TuneIn Radio might work with no issue, for example), Spotify does require a little more robust of a connection. That said, if you take that speaker and move it physically closer to the router, do the issues persist?
Do you have any Sonos devices plugged into the network via Ethernet cable? You may want to check out this helpful article that explains the difference between using a wireless and wired setup.