Can't Access additional inventory from colossal capacity titan passive

Right now there's no way to access additional inventory space gained from Colossal capacity Titan ascendancy passive while playing on xbox.
While trying to select it in inv menu, trade with npc or storage, the pointer just goes around to belt slot or 2nd set weapon.
There isn't any button prompt on the bottom of the screen, nothing.
How am i supposed to take out items from that additional slots ?