Sorry, I don't know about the random running other than maybe your analog stick controlling it is getting stuck?
I have a different problem since early build in the game onward as well. When I'm casting spells on a mob, the cursor randomly switches targets from the mob back unto myself. I'm not pressing the dpad or anything that would normally change target focus, I'm usually just spamming the x button and nothing else when it happens. It's happened across multiple brands of controllers and drivers so either I'm somehow doing something wrong (most likely) or the game has a strange quirk to it (maybe?).
Anyone else have this problem or have a helpful suggestion? I'm not a gamer please don't suggest pc controls I do not understand how to use them.