I've observed the following behavior on my v60 when in a place that has no T-Mobile coverage and is forced to connect to certain Sprint bands (seems to often involved 800 MHz).
1.) The phone connects to LTE.
2.) The phone *briefly* displays the VoLTE icon, but it almost immediately disappears as if the connection has failed.
3.) The LTE indicator switches to R, indicating roaming.
4.) The radio completely resets, and begins searching anew for a network. (A particularly obnoxious side effect is that this cause to Android Auto to disconnect/reconnect as well)
When the phone *does* behave well on Sprint 1900, I note that it doesn't attempt to connect to VoLTE. I suspect that it's not supposed to use VoLTE on a Sprint tower and that's the problem?
I had a call with Tech Support about a month ago, and resetting the profile/data settings is not a fix.
Thankfully, coverage is fine at home on the T-Mobile network. But having the radio reset twice per minute when in marginal coverage is very annoying, especially when it messes with Android Auto navigation.
eh..with that being said..my speeds are better than they were before even in this signal killer lol..even mid day with heavy data traffic.
cant remember if i mentioned this before...but last rumor was theyre finishing out roughly 100 towers per day across the nation upgrade wise
Well, it definitely was the network telling my phone to spaz out.
My phone now can get VoLTE from those Sprint towers. In this state, it is NOT simultaneously connected to 1X800.
6 months of complaining, but I finally have a phone compatible with the Sprint network!