I have a question, when the RMX register to GK (VCS). the signaling IP is unable to call? is it working per design or it's an issue?. because some of our user didn't wont the endpoint register to the GK, they just want to dial IP signaling##Meeting room ID.
I guess your issue is related to VCS configuration.
there is a possible call flow between your unregistered endpoint and RMX:
for example there are some reasons, why the a call is not established
take a look at VCS's logs and attempt to find a reason of your issue
Thanks for your comment.. I will try that option tomorrow during my onsite support. polycom support also advise that we should use Conf_ID@RMX_Signaling_IP
I will update the result later.