I have been having the problem for a while too. Almost a year at this point. Today, I finally decided to toy with the settings a little bit. I went into the EPST Edit Mode (##778#) and tried all the things that everyone has suggested so far. That didn't work, so I tried the following. So far I have not seen the 4G break connection and I have run multiple successful speed tests with no break in connection. Modem Settings->Preferred Mode (Automatic), Preferred Mode(9k) (LTE only), Rev. A (eHRPD). I hope this helps.
And I just realized, while the data works flawlessly, now, the phone will not work in this area on that setting. Guess I will have to switch it back and suffer until the new phone gets here. But since VZW wants to play dirty, I will too. I will stream everything through my phone to my TV via the HDMI. I will make use of the unlimited plan.
Plus protected (digital rights) programs won't stream to a TV either.
The Tbolt does have DLNA, I believe.
I'm most definitely NOT a VZW employee. If a post answered your question, please mark it as the answer.