Message+ App - badge number does not clear

I migrated from a Samsung Galaxy S8 to an iPhone 8, I use Message+ on my iPhone just like I did on my S8. On the iPhone Message+ app, my badges says I have 4900 messages. Then, open the app and the badges clears. Then, I get a new message and it says 4900 again.

How do I get this to clear so it doesn't keep saying I have thousands of messages?

Re: Message+ App - badge number does not clear
Customer Service Rep

Congratulations on your new iPhone 8. Let's work together on the Verizon Messages notification issue. Is your Samsung device still powered on? If you open Verizon Messages+ in the App store, is there an option to update or remove it?  SheritaH_VZW