IMAP error

Checklist

• I have used the search function to see if someone else has already submitted the same bug report.
• I will describe the problem with as much detail as possible.

App

Thunderbird for Android

App version

16.1

Where did you get the app from?

F-Droid

Android version

HyperOS2 - Android 15

Device model

peridot

Steps to reproduce

GMX (provider) Inbox not updated when connected via WiFi in Finnland. K9 reporting authentication error. However, update works totally fine via mobile data once WiFi is switched of.

Expected behavior

IMAP should work, obviously.

Actual behavior

Just got in to another EU country. Roaming working fine and inbox receives updates. After checking in the WiFi in my temporary home, updates stop once the device is connected to WiFi. After disconnect everything fine (with mobile/roaming data). WiFi without any frills and no VPN. Internet connection via WiFi fine as well in browser. Several other inboxes from other providers receive updates as well.

Logs

No response

No source file, test, or entry point is named. Start by reproducing the GMX IMAP authentication failure on the reported WiFi connection versus mobile data, then gather logs and compare the two paths; done means the cause is identified and the inbox updates reliably over WiFi.