Nokia Lumia 928 connection issues

I have one user with a windows phone , who has been experiencing problems connecting consistently to our GMS server. It will work for a short period of time and then stop with error 85010014. Looked up the error and it seems to be a pretty generic activesync error. He then has to restart his device for it to begin working again. Tried the normal stuff of removing/adding the account on the phone and then re-initializing his account. Other suggestions ? Anyone else have issues with windows phones ? Running GMS 2.01 build 53