I was like level 7 or something. Do you have the Twitch Prime level thing underneath? That seems to get xp as well and I don't know if that has anything to do with it.
So you were able to access the unlocks in customization? Because I am having the same issues as everyone else. There is a visual progression when I claim the xp but once I go back to the main menu it resets and I have not unlocked anything. I know someone earlier mentioned the twitch prime set and I too wonder if that has something to do with it.