Noticing that at times inventory classes are max'ing out at 4 instead of 9 for UA.

Using the Availability tab, FS method.

Example UA 1636 (SFO-ORD), July 11 F4Y4
but UA reports F9Y9 via expert mode.

As you go forward into Aug, Sept, .... this becomes more common and until nearly all flights inventory classes are capped at 4 instead of the normal 9.

I have traditionally used the Award/Upgrade search (but no more for UA), so is this normal or what???