Telling us a little bit about the history of a device may help us suggesting solutions.
Is this a brand new unit or a used unit that work prior?
The PoE comparison only tells us that the cable supplies power to the unit but the network park behind this may be fried.
I suggest you RMA the unit if still in warranty.
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