Move away from Polycom - Here: Polycom - Valet Park Retrieval quit working with EPM Update - Commercial Modules / Endpoint Manager - FreePBX Community Forums
Basically Polycom could give a flying rat’s keister about supporting the Asterisk/FreePBX community and it shows the deeper you dig into their phones - save yourself a LOT of grief and just use Sangoma, Digium, or Yealink phones - your choice, but steer clear of Polycom.