Recent call list not current on VVX400 phones on NetVanta 7100
I've got a NetVanta 7100 running R11.4.5.E with fourteen VVX400 phones connected to it. I'm having an issue with the Recent Call List not displaying recent calls. I've experienced the issue with the phones on both 18.104.22.16830 and 4.1.8.0628. It seems that although Polycom has much newer firmware for the phones, 4.1.8.0628 is the most current supported by Adtran; at least it's the most current on the website. As an example of the issue, I checked all phones on 11/28/16. Only 4 of them had an up to date Recent Call List. There are 4 phones in the Ring Group that rings on all incoming calls, and all of these had a most recent call dating from 11/16/16. If I reboot the individual phone, even during a firmware update, it seems to hold onto its call list. If I reboot the NV7100, the call list clears and seems to work okay for a few days, but then stops updating. Any help is much appreciated.