Unread indicator not shown for thread with an unread message

Steps to reproduce

1. Open mail app and select a message thread with multiple unread messages
2. Read the latest message in the thread, but do not read all new messages
3. Exit message and go mack to inbox

A '1' will be shown next to the inbox on the left, indicating that there is an unread message waiting. However, none of the messages in the list will have a dot displayed indicating that they contain the unread message.

Expected behavior

The thread containing the unread message(s) should display the dot indicating that there are unread messages waiting to be read.

Alternatively, the user should be able to disable message threading so that each mail message is displayed independently in the list. This is how god intended email to work.

Actual behavior

No dot is displayed.

Mail app version

2.1.0

Mailserver or service

Personal domain

Operating system

Ubuntu 22.04.1 LTS x86_64

PHP engine version

PHP 8.1

Web server

Apache (supported)

Database

PostgreSQL

Additional info

No response

Reproduce the issue in the mail app using a thread with multiple unread messages: read only the latest message, return to the inbox, and verify the unread indicator. The work is done when the thread shows a dot while any message remains unread, or when the requested threading alternative is addressed; the payload names no files or tests to start from.