I have the same problem.  The question asks about Windows 10 -- so not a phone!

It just started to happen for me.  It may have been after a recent Windows Update.

The Windows Notification area shows the "Verizon Messages" header and the red icon, but for each and every message in the notfication area, it only ever shows a "Verizon Messages" header, the text "New notification" and the timestamp. Clicking the notification does bring you to the app (presumably to that message, I haven't made sure of that).

If it can no longer show any useful information in the Notifcation area, I'd like a way to just turn that off!  (Frankly I have considered turning it off anyway, something like a badge on the task bar would but plenty sufficient for me.)

Also I second the complain about the terrible problems with syncing with this app on Windows (10) and other devices.  I frequently miss messages here, but more often than that, other devices don't receive my messages that I create in the Windows (10) app.

Is anybody listening that can actually fix these problems!?!?