Bug: "Mark all as read" causes all future emails to be automatically marked as read (Thunderbird Android 10.0)

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

10.0

Where did you get the app from?

Google Play

Android version

11 (MIUI 12.5.15)

Device model

Xiaomi redmi note 8 pro

Steps to reproduce

1. Open Thunderbird on Android.
2. Go to your Inbox.
3. Tap the three-dot menu in the top right corner.
4. Tap "Mark all as read".
5. Wait for a new email to arrive.
6. Observe that it is automatically marked as read, even though it was not opened.

Expected behavior

Only the emails that were in the inbox at the time of selecting "Mark all as read" should be marked as read. Any future emails should remain unread until the user opens them or manually marks them as read.

Actual behavior

Every new incoming email is automatically marked as read after the "Mark all as read" option is used, even though the user hasn’t opened them. This behavior persists until the app is reinstalled or its data is cleared.

Logs

No response

No files or tests are named. Reproduce the issue in Thunderbird for Android 10.0 on Android 11, then trace the "Mark all as read" action and the state that persists for incoming messages; it is done when newly received emails remain unread after the action.