Unable to see messages in a specific group chat on my iPhone

For the last several months, I have not been able to see messages in a specific group chat. I will get notifications for new messages in the chat and am able to read the new message on the banner on the lock screen. However, when I open the group chat all I see is a message from months ago. Basically it looks like it is deleting or failing to show the last two months of messages in the chat. If I open the info section of the chat I can see any attachments that have been sent recently but they also are nowhere to be found in the thread itself.

Yes, I have restarted the phone.

Yes, I have toggled off/on every setting in the messages app.

Yes, I have updated to the most recent software.

[Re-Titled by Moderator]

Original Title: Group messages not appearing