Yesterday, I got a battery replacement on my S6.

Today, I realized I could not get any connection to the Sprint Network. No LTE coverage, only roaming coverage, or none at all. Until I got to the Sprint Store, where it immediately connected to LTE and let them do all the updates. They pronounced it cured, I got less than 1/4 mile from the store, where it promptly dropped the call I was on, and went to roaming, then no signal at all. Drove immediately back to the Sprint store, where they rebooted it, and it immediately connected to LTE and started working. They did a PRL update, a profile update, and said well, if it doesn't work when you get home, we'll replace it. (With the 200.00 deductible since they claim no physical damage.)

Same thing. Got 1/4 mile away, went to roaming, then dropped the network. I got annoyed, and did a factory reset, and cleared the cache. Phone worked for maybe 20 minutes, then dropped. It only works on WiFi and WiFi calling. If I take it off WiFi, it goes to roaming, then off the network. I drove all over the county for work today, and it refused to connect to any network along the way. I think it picked up LTE one time, by another Sprint Store.....

I've taken it off Automatic and put it on LTE/CDMA and turned off the optimizer as well. This worked the first time I had these problems. It's just strange that it ONLY works at the Sprint Store.

Any ideas? Sprint can't get me a new phone till Friday.