thunderbird-android Mail not fetching automatically in background or on app open (manual sync required)

Checklist

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

App

Thunderbird for Android

App version

10.1

Where did you get the app from?

Google Play

Android version

14

Device model

kb2003

Steps to reproduce

Configure an account in Thunderbird for Android (multiple Microsoft and Gmail in my case)
Set polling interval to 15 minutes
Enable "Background sync" (set to "Always")
Ensure battery optimizations are disabled for the app
Make sure background activity is enabled in Android settings
Wait 15 minutes or open the app — no sync occurs
Manually sync via pull-down — mails are fetched immediately

Expected behavior

Thunderbird for Android should automatically fetch mail in the background at the specified polling interval (15 minutes in my case), or at the very least, initiate a sync when the app is opened.

Actual behavior

Mails are not fetched automatically. Even when I open the app and wait, no sync occurs unless I manually trigger it (pull-to-refresh or press sync). This defeats the purpose of background sync and notifications.

Logs

No response

Jun 28 '25 16:06 Drarox

Drarox, Thanks for the report. Did this work for you in previous releases?

Jul 07 '25 14:07 coreycb

@coreycb This is my first time using Thunderbird or K-9 Mail, so I can't say. I just downloaded the app and added my Microsoft and Gmail addresses like any regular user and it's not working, even with the app opened.

Jul 07 '25 18:07 Drarox

I have the same issue.

Account : iCloud Device : ZFold 6

Background sync does only work when device is unlocked