Here's a weird twist. Sound comes through headphones but not through the speaker.
Only on the TPA app.
Agreed, but with the oddity of the issue, you never know what will actually end up fixing it. If a complete app deletion/re-installation didn't help, it's pretty much grasping at straws time.This crossed my mind as well. But it is only effecting one app.
If that doesn't help, check your iDevice's side switch settings (assuming the device is an iPad)
This crossed my mind as well. But it is only effecting one app.