Issue with the integrated inbox

Start by reproducing the issue from the reported Unified Inbox steps with four configured accounts, then trace the Unified Inbox refresh or message-display entry point. Compare opening the individual account Inbox with opening Unified Inbox after background receipt. Done means newly received messages already visible in account inboxes also appear in Unified Inbox immediately when the app opens.

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

22.0

Where did you get the app from?

Google Play

Android version

16

Device model

Motorola Razr 50 Ultra

Steps to reproduce

1. Configure four email accounts in Thunderbird for Android.
2. Enable Unified Inbox for all four accounts.
3. Make sure all accounts are working correctly and that new emails are received normally.
4. Close Thunderbird.
5. Send a test email to one of the configured accounts.
6. Wait until Thunderbird receives the new email in the background.
7. Open Thunderbird.
8. Thunderbird opens in the Unified Inbox.
9. The newly received email is not displayed in the Unified Inbox.
10. Open the individual account that received the new email.
11. The new email is immediately visible in that account's Inbox.
12. Return to the Unified Inbox.
13. The same email is now visible in the Unified Inbox.

Expected behavior

When Thunderbird is opened, the Unified Inbox should immediately display all emails that have already been received and are available in the individual account inboxes.

Actual behavior

Thunderbird receives the new email correctly, but the email is missing from the Unified Inbox when the application is opened.
The email only appears in the Unified Inbox after opening the individual account that received it.
The message is therefore already present in Thunderbird, but the Unified Inbox does not appear to update/display it until the corresponding account's Inbox is opened.

Important observation

This does not appear to be an email delivery or background synchronization problem.
The email has already been received by Thunderbird and is immediately available when opening the corresponding account's Inbox.
The problem appears to be specifically related to the Unified Inbox not displaying newly received messages until the individual account's Inbox is opened.

Logs

Since the update before the latest one, I've been having a problem with Thunderbird's Unified Inbox.
I have four email accounts configured. Emails are delivered normally to the individual accounts, but they don't immediately appear in the Unified Inbox.
In order for a new email to appear in the Unified Inbox, I first have to open the inbox of the specific account that received the email. Only after I enter that account's inbox does Thunderbird seem to detect/refresh the message, and the email then appears in the Unified Inbox as well.
Previously, everything worked correctly — every new email appeared immediately in the Unified Inbox without having to open the individual account first.
Thunderbird 22.0 was released today, but unfortunately the problem still persists.
Has anyone else experienced this issue? Could this be a bug in Thunderbird, or is there some setting related to the Unified Inbox that I might be missing?