FWIW, I have been experiencing the same thing with multiple T650/700P's. During my first 12 mos of service calls were dropped daily at all locations/times. This cleared up for 5 mos and has now become even worse. Sprint has sent techs up
their 2 towers nearest to my main residence to check the equipment (there are 5 different carrier's towers near this residence as well). I am able to verify this as they phone me while on the tower and usually waive as they are well aware that we are able to see one another.
My devices are now constantly switching from provider to provider and from Sprint to roaming even more often. Often I wait for a call to go through and the devices simply time out. Sprint has also taken care of re provisioning their towers and all devices remotely as well as physically to no avail.
These issues have been occurring even more frequently as of late throughout the entire Phoenix metro area with no explanations. As we all know, dropped calls are a part of the cell "game" and to be expected but ....... I would not normally post anything of this nature but it has been extremely abnormal and YOU started it.
Data communications have been acting similarly. Good luck to one and all in this thread. If anyone else has ideas/comments...