Sent from my SM-N900T using XDA Free mobile app
I get three bad behaviors from HD Voice (VoLTE) on my Note 3:
1) Incoming calls don't go through
2) Cannot place outgoing calls
3) Dropped calls
For #1 and #2, it seems to have to do with the flaky LTE by my work. I work at a campus filled with nearly 10,000 engineers and techie people. The LTE here is almost unusable because of the load. When I go to make a call, it says "HD Voice" then "Failed to connect" or similar. There is -no- workaround. I end up calling on a landline.
The #3 issue I'm seeing at home as well as work. I get calls dropped, usually when I am moving from one location to another. I think the issue is getting handed off from a LTE to 3G connection. This handoff is fatal and drops the call. I get pretty good 3G where I live, and LTE through most of the house. But if I start a call in one side of the house, and move to the other side of the house I lose the call. It is extremely frustrating.
If they are caused by volte you can go to settings/devicetab/call and turn it off. That should stop or minimize those behaviors for you as it did for me. Although now with the latest nf4 update Tmo rolled out which concentrates mostly on Volte it seems to work much better.