Badge for Messages App Won't clear

On my iPhone XS, on the Home screen, the Messages app has a badge stuck at 3, even though I have no unread messages. It's been like this for several days. I just upgraded to IOS 13.5.1 - doesn't help. Also:

I tried to power off, then back on, the phone - doesn't help.

If I turn Settings -> Notifications -> Messages -> Badges off, the Badge icon will go away, but it comes back stuck at 3 if I turn Badge notifications back on.

I guess I can live without Badge notifications for Messages, but this stuck Badge notification counter is annoying.

Any ideas? If I have to reinstall the phone I'll need some help.

Thanks!