Playing fallout 4, made Piper run around in her underwear for a minute, & put clothes back on. After that all companions & settlers clothes are hidden from me. What's with this, does any one know? on xbox one.

Yup, default clothes is always hidden on NPCs. You can have them equip clothes that won't fit under armour - like the tuxedo - equip some leather armour, and then remove the armour and they will be back in their underwear.