I recently upgraded from a droid turbo to galaxy S7. Both mobile hotspot and my Verizon apps worked up until the minute I handed my old phone over.
Now, on the new phone with My Verizon, I get a sign in error saying "We were unable to launch my Verizon with a number associated with your device." It will let me log in manually with my mobile number though.
With Mobile hotspot, I just get a message saying "unable to connect. mobile number not found"
It would seem like a setting is off somewhere in the phone but Google searching isn't being very helpful as far as finding a solution.