Hello! This is a known issue and there is a workaround:
While in the Champion menu for your preferred Allegiance, simply select to change an Item. This can be ANY item from your Armor, Spells, Weapons, and Relics options. You can even just re-confirm you current chosen item. This will ensure your current chosen Allegiance is gaining XP earned.
You can use this workaround before you select a game mode/Quick Match or while in the countdown menu.
Found a new bug, or at least an annoying behavior:
Whenever I fire up the game, I MUST watch the initial cutscreen; can't hit START to skip past it.
you can skip it by press X.