Radio streams stopping after a bit

I have a problem with playing radio streams. I can start a stream via Radio -> Local -> Stations -> any station, or by just hitting Play when I also last played the radio station. However, after a while, the stream just stops playing. This can be after an hour or after 5 minutes.
I checked multiple stations and all stations have the problem. Also, this is normally on my Squeezebox Classic, but I tested with the SqueezePad app on my iPad and it behaves the same as well. So I think it's an issue with my LMS.

However, I can't see anything in the logs related to this. No new log entries when the problem occurs. I do see other errors/warnings but they are not related AFAIK.

[19-02-09 12:53:00.3237] Slim::Networking::Slimproto::client_readable (414) Client not found for slimproto msg op: STAT from 192.168.22.39
[19-02-09 12:53:45.1222] Slim::Utils::OS::Win32::getPriorityClass (752) Error: Slim::Utils::LogCan't get process handle () [Wrong number of parameters: expected 0, got 1.
]
[19-02-09 13:23:15.2744] Slim::Utils::Timers::__ANON__ (273) Error: Timer Slim::Plugin::UPnP::Events::expire failed: Can't call method "pluginData" on an undefined value at C:/PROGRA~2/SQUEEZ~1/server/Slim/Plugin/UPnP/MediaRenderer/AVTransport.pm line 216.
[19-02-09 13:23:16.0391] Slim::Utils::Timers::__ANON__ (273) Error: Timer Slim::Plugin::UPnP::Events::expire failed: Can't call method "pluginData" on an undefined value at C:/PROGRA~2/SQUEEZ~1/server/Slim/Plugin/UPnP/MediaRenderer/RenderingControl.pm line 161.
[19-02-09 21:54:55.4204] Slim::Networking::Slimproto::client_readable (414) Client not found for slimproto msg op: STAT from 192.168.22.39
[19-02-09 22:25:07.1026] Slim::Utils::Timers::__ANON__ (273) Error: Timer Slim::Plugin::UPnP::Events::expire failed: Can't call method "pluginData" on an undefined value at C:/PROGRA~2/SQUEEZ~1/server/Slim/Plugin/UPnP/MediaRenderer/RenderingControl.pm line 161.
[19-02-09 22:25:07.1099] Slim::Utils::Timers::__ANON__ (273) Error: Timer Slim::Plugin::UPnP::Events::expire failed: Can't call method "pluginData" on an undefined value at C:/PROGRA~2/SQUEEZ~1/server/Slim/Plugin/UPnP/MediaRenderer/AVTransport.pm line 216.
[19-02-09 22:30:15.0079] Slim::Utils::Timers::__ANON__ (273) Error: Timer Slim::Plugin::UPnP::Events::expire failed: Can't call method "pluginData" on an undefined value at C:/PROGRA~2/SQUEEZ~1/server/Slim/Plugin/UPnP/MediaRenderer/RenderingControl.pm line 161.
[19-02-09 22:30:15.0090] Slim::Utils::Timers::__ANON__ (273) Error: Timer Slim::Plugin::UPnP::Events::expire failed: Can't call method "pluginData" on an undefined value at C:/PROGRA~2/SQUEEZ~1/server/Slim/Plugin/UPnP/MediaRenderer/AVTransport.pm line 216.
[19-02-10 09:42:25.0833] Slim::Networking::Slimproto::client_readable (414) Client not found for slimproto msg op: STAT from 192.168.22.39
[19-02-10 10:12:55.1336] Slim::Utils::Timers::__ANON__ (273) Error: Timer Slim::Plugin::UPnP::Events::expire failed: Can't call method "pluginData" on an undefined value at C:/PROGRA~2/SQUEEZ~1/server/Slim/Plugin/UPnP/MediaRenderer/AVTransport.pm line 216.
[19-02-10 10:12:57.0269] Slim::Utils::Timers::__ANON__ (273) Error: Timer Slim::Plugin::UPnP::Events::expire failed: Can't call method "pluginData" on an undefined value at C:/PROGRA~2/SQUEEZ~1/server/Slim/Plugin/UPnP/MediaRenderer/RenderingControl.pm line 161.
[19-02-10 11:41:16.5985] Slim::Networking::Slimproto::client_readable (414) Client not found for slimproto msg op: STAT from 192.168.22.39