Total stab in the dark here, but it could be the local time on the device. Your local clock needs to be relatively close to the actual clock. I've run into this more than a few times with an old Surface Tablet I seldom use. Powered off/battery dead, clock gets out of sync. Power on, cannot get online because everything is TLS/SSL now, even clock sync. Cannot even sync the clock, because of certificate issues. Manually set the time to approximately correct time has resolved my issues with long powered off devices. That is, assuming of course, the _ability_ to set the time on the device.
> but it could be the local time on the device. Your local clock needs to be relatively close to the actual clock.
Yes, this is one of those nasty hidden costs that the "just use TLS/SSL for everything, it's easy!" people don't seem to recognize - introducing certificates to the mix suddenly makes your application coupled to wall clock time being in sync with the rest of the world. That is a big step in complexity right there - as everyone who ever had a clock drift couple minutes off the rest of the world, and saw half of the Internet stop working for them.
(And don't get me started on getaddrinfo(), another step function in complexity, hard-coupling even most trivial software to a heap of things that isn't relevant to it at all; or how it all interacts with SSL.)
