I'm more than firm that UA is blocking even the impossible, NH.
I was making an booking all summer long trying to match 3 on NH-F. I spent 2 months before I realized what's on UA.com does not match NH. Twice I called UA and both were told no availability.
So no UA is hiding availability that's showing available on Aeroplan and MileageClub.
CA wise all I know is they pulled F awards to T-72 hours.