LG Watch Sport on T-Mobile & PixelXL on Project Fi - Display Number not working

[Android Central Question]

I have LG Watch Sport LTE on a T-Mobile SIM / Number & PixelXL on Project Fi Number. The sync is working fine and call forwarding also working fine.

However, my setup on LG Watch Sport to display the number of my Phone instead of the T-mobile number isnt working. It still shows the TMobile number when I call from the watch. I want it to display the ProjectFi number of my phone.

Any ideas here ? Has anyone experienced this ?