Amazon Echo Control - Websocket errors

The binding works, but I am getting these errors in my log which probably lead to crashed of openhab:

2020-12-14 20:38:27.887 [INFO ] [control.internal.WebSocketConnection] - Web Socket error
java.nio.channels.AsynchronousCloseException: null
	at org.eclipse.jetty.client.http.HttpConnectionOverHTTP.close(HttpConnectionOverHTTP.java:181) ~[?:?]
	at java.util.ArrayList.forEach(ArrayList.java:1257) [?:1.8.0_222]
	at org.eclipse.jetty.client.AbstractConnectionPool.close(AbstractConnectionPool.java:208) [bundleFile:9.4.20.v20190813]
	at org.eclipse.jetty.client.DuplexConnectionPool.close(DuplexConnectionPool.java:237) [bundleFile:9.4.20.v20190813]
	at org.eclipse.jetty.client.HttpDestination.close(HttpDestination.java:385) [bundleFile:9.4.20.v20190813]
	at org.eclipse.jetty.client.HttpClient.doStop(HttpClient.java:260) [bundleFile:9.4.20.v20190813]
	at org.eclipse.jetty.util.component.AbstractLifeCycle.stop(AbstractLifeCycle.java:93) [bundleFile:9.4.20.v20190813]
	at org.eclipse.jetty.util.component.ContainerLifeCycle.stop(ContainerLifeCycle.java:180) [bundleFile:9.4.20.v20190813]
	at org.eclipse.jetty.util.component.ContainerLifeCycle.doStop(ContainerLifeCycle.java:201) [bundleFile:9.4.20.v20190813]
	at org.eclipse.jetty.websocket.client.WebSocketClient.doStop(WebSocketClient.java:371) [bundleFile:9.4.20.v20190813]
	at org.eclipse.jetty.util.component.AbstractLifeCycle.stop(AbstractLifeCycle.java:93) [bundleFile:9.4.20.v20190813]
	at org.openhab.binding.amazonechocontrol.internal.WebSocketConnection.close(WebSocketConnection.java:159) [bundleFile:?]
	at org.openhab.binding.amazonechocontrol.internal.WebSocketConnection$2.run(WebSocketConnection.java:184) [bundleFile:?]
	at java.util.TimerThread.mainLoop(Timer.java:555) [?:1.8.0_222]
	at java.util.TimerThread.run(Timer.java:505) [?:1.8.0_222]

Any ideas?