Quick Feedback:
XP:
Pre 30 (Normal): Works perfectly. You get points and even after swapping characters and reloading the correct level gets displayed in the top left.
Post 30 (Mastery): It is stuck at Level 1 (Or Mastery, whatever its called). While you get Points, the game still thinks you are Level 1.
To further explain:
Lets assume you are mastery 20 and look at your loadout tab or your squad tab.
You will see that you are mastery 20. And you will have 20 mastery points to spend. So far so good.
But when you swap characters or load in you will see a xp bar in the top left corner displaying lvl 1. This doesnt happen when you are just leveling.
Maybe this is something fixable maybe not. You did it with the normal levels maybe you can do it with the mastery levels too. Anyways amazing work