welcome to the Polycom Community.
There are Parameters that can be adjusted via configuration files that are loaded from a provisioning server but these are usually optimized for the best values.
At this point it would be interesting if you could check the Software Version of the actual unit as a Software Upgrade may improve the experience you and your customers had so far.
Usually Polycom resellers are the point of contact for any support related issues but you could try and follow this guide that explains how to load a new Software Version via a freeware FTP server.
I would recommend the UCS 3.3.1 Rev F and the BootROM 4.3.0 here
Please make note of the SIP Credentials and Passwords.
Polycom Global Services
If official support is required please check how to phone or open a case here----------------