Sounds like a Facebook bug you would need to contact Facebook support
If you've found my post to be helpful, Please like my Comments ✓✓✓. If my response resolved your issue, please press the Like and ✓✓✓ to Accept as Solution button.
I'm having the same issue. Very frustrating. I've uninstalled, restarted the phone and reinstalled a few times..unpredictable when messages wills go through.
