UA customer service can come through.
So we are booked SFO-(UA)-LAX-(UA)-FRA-(LH)-PRG. No award space on the SFO-FRA non-stop. I had purchased a ticket and upgraded, the other was mileage award. I then used BMI miles for my FRA-PRG on LH. Of course then UA cancels LAX-FRA, and automatically rebooks us on SFO-FRA non-stop - which is great, I didn't really want to connect through LAX. But this causes an 8 hour layover in FRA, not so fun. ANA site shows tons of seats available on the earlier FRA-PRG flight, but when I call UA says they don't even see that flight in there system (as the recent blocking that has been reported). Today I decide to call again. After all this is not going to cost them extra $, just a change of flight times. She again doesn't see it in her system, I ask if there is anyway they can contact LH. She puts me on hold to contact her award desk - 5 minutes later rebooked on the earlier flight. Now I just have to wait for BMI to open so I can change mine, plenty of seats so not sweating too much.
Thanks UA - it's nice when you go the extra mile!