I booked a one-way award with 3 legs: OS in J (VIE-LHR), UA in J (LHR-DEN), and UA in Y (DEN-SNA); and even during the booking UA website showed that only 2 legs would count for PQF and PQP.

Essentially, Why?

The OS flight had a different reservation code (which I used to check-in for the flight... that was its own problem as 2 of the tickets were for children, but OS thought they were adults. So, when I tried to use their birthdays during check-in, the OS website and an error and there was no way around it. Even at the VIE airport counter, the man started by acting very unsure that a reservation for children listed as adults would go through... but it did go through and we got boarding passes).
For that OS flight, I made sure the UA FF# was on the tickets. - but that leg hasn't shown up in my account.

And, do I need to ask about lifetime miles for that leg (Extremely minor point...)

Thanks much.