Spotify binding Media Control

Hi,
I’m trying to add Play/Pause/Next/Previous commands buttons to habpanel using 3.0.2 Spotify Binding. For some unknown reasons they are not working. I already added track name, artist name, track duration and so on without problems.

It seems that the media control channel works only from the paper ui.

From console if I send PAUSE it will change to PAUSE and revert back to PLAY but without really pausing the stream.

openhab> openhab:update mediaPlayer PAUSE
Update has been sent successfully.

13:48:54.300 [INFO ] [openhab.event.ItemStateChangedEvent  ] - Item 'mediaPlayer' changed from PLAY to PAUSE
13:48:56.335 [INFO ] [openhab.event.ItemStateChangedEvent  ] - Item 'mediaPlayer' changed from PAUSE to PLAY

And from habpanel I get an unsupported media type error

ng-click="sendCmd('mediaPlayer', 'PAUSE')"
13:55:31.394 [ERROR] [org.apache.cxf.jaxrs.utils.JAXRSUtils] - No message body reader has been found for class java.lang.String, ContentType: application/octet-stream
13:55:31.395 [WARN ] [rs.impl.WebApplicationExceptionMapper] - javax.ws.rs.WebApplicationException: HTTP 415 Unsupported Media Type
        at org.apache.cxf.jaxrs.utils.JAXRSUtils.readFromMessageBody(JAXRSUtils.java:1382)
        at org.apache.cxf.jaxrs.utils.JAXRSUtils.processRequestBodyParameter(JAXRSUtils.java:877)
        at org.apache.cxf.jaxrs.utils.JAXRSUtils.processParameters(JAXRSUtils.java:822)
        at org.apache.cxf.jaxrs.interceptor.JAXRSInInterceptor.processRequest(JAXRSInInterceptor.java:214)
        at org.apache.cxf.jaxrs.interceptor.JAXRSInInterceptor.handleMessage(JAXRSInInterceptor.java:78)
        at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:308)
        at org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:121)
        at org.apache.cxf.transport.http.AbstractHTTPDestination.invoke(AbstractHTTPDestination.java:267)
        at org.apache.cxf.transport.servlet.ServletController.invokeDestination(ServletController.java:234)
        at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:208)
        at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:160)
        at org.apache.cxf.transport.servlet.CXFNonSpringServlet.invoke(CXFNonSpringServlet.java:216)
        at org.apache.cxf.transport.servlet.AbstractHTTPServlet.handleRequest(AbstractHTTPServlet.java:301)
        at org.apache.cxf.transport.servlet.AbstractHTTPServlet.doPost(AbstractHTTPServlet.java:220)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
        at org.apache.cxf.transport.servlet.AbstractHTTPServlet.service(AbstractHTTPServlet.java:276)
        at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:852)
        at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:544)
        at org.ops4j.pax.web.service.jetty.internal.HttpServiceServletHandler.doHandle(HttpServiceServletHandler.java:71)
        at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
        at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:536)
        at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
        at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:235)
        at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1581)
        at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233)
        at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1307)
        at org.ops4j.pax.web.service.jetty.internal.HttpServiceContext.doHandle(HttpServiceContext.java:293)
        at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:188)
        at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:482)
        at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1549)
        at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:186)
        at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1204)
        at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
        at org.ops4j.pax.web.service.jetty.internal.JettyServerHandlerCollection.handle(JettyServerHandlerCollection.java:80)
        at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
        at org.eclipse.jetty.server.Server.handle(Server.java:494)
        at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:374)
        at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:268)
        at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311)
        at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:103)
        at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:117)
        at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:336)
        at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:313)
        at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:171)
        at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:129)
        at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:367)
        at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:782)
        at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:918)
        at java.base/java.lang.Thread.run(Thread.java:829)

Any ideas?
Thank you!