Anyway i take it in TTRPG it still doesn't stack?
No, you can only use 1 AC calculation at a time, so unarmoured defence won't stack with mage armour, or the draconic Sorcerer's scales, or the Monk's version of unarmoured defence (just in case you want to try multi-classing Monk and Barb).
Pretty much the only stacking AC effects in 5e now come from putting on a shield, and then putting on a magical item like the aforementioned bracers of defence.
unfortunately you can't dismiss mage armour, you're going to have to long rest to make it expire, or try using dispel magic.
