I have no idea if our postings can attract any responsible and/or capable people from Verizon, who can investigate/fix this Messages failure.
If we can get some attention, it might help them if you can identify your exact version of Windows 10.
In case you are (or anyone else is) unfamiliar with how to find that; tap the "Windows" key, then type "winver" and tap "Enter".
A window should pop up with the details, like the ones I provided above.
Wish us luck!