I just switched to Sprint in January and chose the Windows Lumia 635. I have had nothing but problems since I walked out of the store. My date and time randomly change. Even if I set it to update automatically, it won't. I have to manually set the date and time and then it changes whenever it wants too. Just the other day it chose a day in November?!?!? I had my email accounts set up and then all of a sudden the notifications stopped. I deleted all of the email accounts and tried to set up again and the phone won't allow me to do it. This is a major problem for me as I get work email and have my own private company and need to be able to read emails daily. There are several other issues but these are the major ones. I have taken the phone to the Sprint store at least 3 times since I got it. They are no help and say that I have to pay off the stupid ass phone before I can get another one. So not happy that I left AT&T for this.
The Sprint employees don't know anything about the OS, so it's no surprise they're not able to help.
Go into your settings and change the tab for set Date/Time to manual. Then put in the correct ones.
I have had the same issues you noted. My HTC Windows phone broke, and I bought this phone outright to buy time until the new Windows Phones arrive on Sprint (not sure if that will happen now - can't find any information or updates). I have loved my Windows phones, but Sprint has never been able to provide customer service on it. My last phone had bugs/issues with it, and every time I brought it in they said it was the first time they heard of the issue. I live in a fairly small city, and I brought my phone in at least three times with the same issue, and always the same technicians. So, I'm not sure how they claimed ignorance after the first one, or even two times. Not only that, but on all these phones, I can easily Google an issue and see where it's provided problems for other issues. It concerns me that the customer service technicians know nothing about these phones or the OS. Most of the time I wind up researching my own fix online since I know Sprint will be useless.
As for this particular phone, it has been a disaster since I bought it. I have children, so the lack of flash is frustrating (though, of course I knew this when I bought it and was just using this as an intermediary phone). When browsing the internet on this phone, it constantly crashes and goes back to the home screen. My time on my texts is all off. I didn't care about this at first, until I would get messages asking if we could get our kids together at a certain time, or asking if we were around, and I'd have no idea when the text was actually sent. The time stamp on my outgoing texts seems to be ok, though. I have tried to manually set the time, and used automatic, and I can't correct it.
I think it's about time to give up on the Sprint + Windows combination. They obviously are never going to do anything to help support Windows. I even took my phone to a store in NYC on vacation, and even in a large store they originally told me it couldn't hold a memory card (it could), then had no idea where it went. Seems a little ridiculous.