You are outputting 20V on the carnetix into the PicoPSU?!
The PicoPSU DOES NOT REGULATE THE 12v LINE. it takes whatever you send in as 12v exactly. That is why it is not made for car use.
So if you are feeding 20V into the picopsu, then all the devices that are using 12v, are getting 20v and you could have blown them.
PicoPSU is meant only for house use.