After over a month of connection difficulty at work (thirty miles from where I live) but not at home, I thought the problem had finally resolved itself, and right on time for the Fire and Ice event!
Unfortunately, my issue began again
earlier this afternoon (er, yesterday afternoon), and this time where I live rather than where I work. I lost my connection, was unable to log in after restarting the app and twice
restarting my phone, and the app is now "unable to authenticate" my account since, in a fit of desperation, I decided to try re-entering my login information.
A quick Google search (which I should probably have tried ages ago) reveals that this is apparently a common problem for people logging in with their Pokemon Trainer Club account, of which I am one.
If anyone knows of a way to fix this, I'd love to hear it; I really don't
want to just start a new game with a fresh account, but I also don't want to drive half an hour on the off-chance that being in the city where I work helps.
Edit: Force-closing the app also didn't help.Edit 2:
The fantabulous catness
has provided a working fix
! I will note that I had to do a bit of extra searching to find an old version of Pokemon Go to install, and fiddle with my phone's settings to allow it to boot, but it did indeed work.
I will also note that some searching tells me that the PTC login issue is only a problem on Android
phones; iPhones seem to have no problem logging in with either account type.