K9 not sending or recieving

All of a sudden, k9 not sending or recieving email on any account. In sending, mail goes to outbox and sits. When I swipe down on inbox or other folder, the spinner just spins. Been using k9 for years, this is a first.

Ok… problem solved by rebooting phone.

Seems odd, as everything else was working. Facebook, browser etc… but there ya go.