Just to preface this, I don’t actually use this particular DTH, so I’m just basing suggestions off of common issues I’ve seen elsewhere. 
Have you tried those URLs directly in your browser and do they work as expected?
http://172.16.0.241:9000/status.html?p0=pause
If the device was manually created in the IDE, did you make sure to assign it to your Location/Hub?
Is there any logging or diagnostic tools available on the PiCorePlayer (PCP)? Would be helpful to see if the command if coming through and PCP just doesn’t like something about the request. For example, I noted that the code always seems to add a Content-Type header of "application/x-www-form-urlencoded". Some web servers can be really particular about the requests they receive… and it’s pretty uncommon to include a content-type with a GET request.