Traveling with my Dad last weekend on the same PNR, I'm a FO, he's no status. I checked us in on Delta's mobile site from my phone then when I got to my hotel later, went to print our boarding passes. Despite going all the way through check-in on my phone, when I logged onto DL.com from the hotel computer we were shown as non-checked in

Had to start the whole process over before I could get BPs.