ShoreTel / Meraki
I'm not sure if this is intended functionality or not, but I have a ShoreTel phone connected to a Meraki - which is connected to the AmplifiHD router, and since the 2.6.0 firmware update it stopped working. It was also not working after the update to 2.6.1
After reading some of these forums and firmware release notes, I enabled the bypass DNS cache setting in the web UI - which seemed to allow the ShoreTel to start working normally again.
Prior to the 2.6.0 update, the ShoreTel and Meraki had been working perfectly without issue.