Only sees last message in thread when swiping/archiving

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 version

6.400

Where did you get the app from?

Google Play

Android version

12

Device model

Oneplus 8T

Steps to reproduce

Have multiple mails in the inbox, some of which are grouped into into a thread, and one of which is not

Tap a non-threaded e-mail to view it

Go to the threaded e-mails, either with the arrow buttons at the top (or swiping in the new version), or by archiving the e-mail, so K-9 automatically jumps to a different e-mail.

Expected behavior

It first goes to the oldest e-mail in the thread (assuming you were viewing an older message and jumped to the next one), and then as you keep archiving/swiping it goes to the next e-mail in the thread and so on.

Actual behavior

It only shows the newest e-mail in the thread, with no way to swipe to previous e-mails.

Logs

No response

Start by reproducing the issue in the Android app using the listed version, device, and steps, then inspect the message-navigation behavior for threaded emails during swiping and archiving. Done means navigation reaches each message in the thread in order, including older messages, rather than only showing the newest one.