notification of message but there is none

So this may be a bug with Facebook Messenger itself... but it's only been happening since the latest update of IOS14.3. (Yes, I just did the 14.4 update and it's still happening), and actually for the past 2-3 of days only.

I have my notifications turned ON (and yes, I want them on) for certain apps.

Facebook Messenger keeps showing the red dot that I have unread messages... but I don't.

Yes I've gone through EVERY message to ensure.

YES I've deleted all message requests and spam.

Yes, I shut my phone completely off, gave it 5 minutes, then restarted.

Yes, I even turned off notifications for messenger... left it for a few minutes, turned it back on. (yes, I rebooted after).

No matter what happens, it is still showing that there is an unread message.... when there isn't.

How do I clear this?? No other app has issues, but I need my notifications on because I have a couple of business conversations that I need there, but I don't want to waste time thinking there's a message when there isn't (or miss an important one when there is).

(Yes, there's a group chat also - but I told it to mute and not show me notifications... unless that's the culprit? But even when I've gone in and read all... the message notification overall still shows even if there's nothing new).

This is ONLY happening with facebook messenger. The facebook app itself has the notifications working properly... so wasn't sure if this was something related to the most recent IOS update, or what.

Thoughts? Any other trouble shooting ideas?