Preview not showing last reply when decrypting previous messages

[sssoleileraaa]

STR

1. in /var/www/securedrop run ./qa_loader.py --journalist-count 1 --source-count 1 --submissions-per-source 500 --replies-per-source 500 --source-reply-fraction 1 just to make sure there are plenty of things to decrypt

2. log into the client

3. select this new source that you just created with the qa loader script

4. send a reply as it's decrypting messages

Expected

To see the reply in the preview and for it to remain there unless a new message or reply comes in with a later timestamp

Actual

The reply shows up in the preview but once one of the older messages is decrypted that message shows up and the preview continuously changes each time something is decrypted.