Most every day the app stops communication with my server. If I try to refresh it just spins forever. Force closing the app and loading it again resolves. Been doing this for a few months now.
Without more specifics (Android version, device, K-9 version, …) it is impossible to help. A debug log may also help.
Are you by any chance running K-9 on a Chinese brand phone? —> Enable background services and Jobs (or FCM) in Chinese ROMs | by Himanshu Singh | MindOrks | Medium
Android version 13, S22 Ultra - SM-S908U1, 6.707, log attached, not a Chinese phone
(Attachment k9mail-logs.txt (1) is missing)
Seems like I can’t include the log.
So use pastebin or one of the other many places online where you can upload text 
Try switch off bluetooth and restart your phone. Bluetooth function seems to damage something in connection with K9.
I will test this. Do I have to leave Bluetooth turned off?
No, after restart and hopefully good connection just turn it on. In my case (mail bofy not displayed) it worked.
No idea what Bluetooth has to do with ot…