Some TuneIn stations will cut off access to reduce idle/dead connections and each station has its own timeout.
The only way to get this resolved is through Control4 tech support (and your dealer if you aren't one), so that they can review the audio logs to determine if some programming is turning it off or if the station is killing the stream.
Also, for the best audio experience, I would suggest you be on Control4 OS version 3.2.4.