In case it helps someone... here's what worked for me just now. Transferred points from Amex MR (instant) and wanted to book *A award for my parents - wasn't aware of the 72 hour rule for nominees. Added them during the booking flow as nominees (again - why would you let people do that if this 72 hour hold exists??), booking errored out on the website at the step of "select seats" or "straight to payment". I then tried the app thinking it's tech glitch - app also errored out but later in the process (after I managed to enter CC). This is when I did research and learned about the 72 hour nominee rule and ways folks have gotten website to do quasi-holds. Lo and behold checked and the failed mobile app attempt seems to have created a PNR I could see on the website. Went in on website and clicked "confirm" booking in the PNR, entered CC info, and it ticketed. Hopefully this helps someone.