I have been having problems since I bought this phone with LoS and had been having bad customer service to the extreme which I won't go into here.
A couple of days ago I did an executive email bomb (not the dan@icouldgive address, but their actual email addresses). Bob Johnson, the customer service top guy at Sprint personally called to apologize to me at 9pm at night. After I explained the issue, he said he would research the issue and get back to me. A top Samsung dev called me today who said he had spoke to Bob and informed me that an update was due in December. He offered to push the update to my phone now but said it was still in testing, so I declined.
He explained the cause of the issue to me. It is isolated to areas with spotty coverage, which is why some don't experience it at all. If you are in 4g and leave 4g coverage, or in 3g coverage and leave 3g coverage, and in the process of sending packets, there is apparently a bug where the phone does not detect this and would just give up after it could no longer talk to the old tower.