The purpose of the Unsupported Android Device post => here <= is to gather details about the device as advised in the post.
Your issue is most likely firewall related and has been discussed on multiple other occasions. Please use the community search to find the relevant post's.
Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.
Polycom Global Services
Notice: This community forum is not an official Poly support resource, thus responses from Poly employees, partners, and customers alike are best-effort in attempts to share learned knowledge. If you need immediate and/or official assistance please open a service ticket through your proper support channels. Please also ensure you always check the VoIP , Video Endpoint , Skype for Business , PSTN or RPM FAQ's