Phone Re-Assignment?

We recently had to reassign a phone to a new user after an employee left and was replaced. The new user was sent an invitation and created a new account. I re-assigned the phone to the new user and everything looks fine in the admin portal.

The problem is, when users receive a call from this phone now (at least internally), the caller ID shows the correct extension number but instead of the user's name, it says "Unused Seat" as though the phone is not assigned to anyone. I also see this on the call logs online. When I open my missed and past calls on my phone, it shows the users name but that might be because I have her added to my directory manually.

Any idea why this might be happening? Does something need to be restarted?