Hey, sorry for not replying sooner.
What do you mean it changes your character's clothes without you doing anything? Sounds like there's some issue with your input, are you using a controller or the keyboard? If you're using a controller then which one? I've only tested the game with Xbox controllers so I don't know what happens with other ones. Or maybe you are clicking the randomize button by mistake (the one down in the middle on the character selection screen).