I am booked in G class from FLL to LAX tomorrow. Upgrade received FLL-IAH, but not IAH-LAX.

I just checked in using the PDA site, and was offered an upgrade for $119 - since the M fare (I'm a Plat) on this segment is $619, and I only paid $275 for the entire round trip ticket, there is NO WAY the $119 represents a M fare buy-up.

This can only be a segment-fee upgrade - which are not suppose to be offered unless there are F seats for every Elite, right?

Yet there are only 7 unsold F seats - and I'm already #3 on the list as Plat, so there is no way the number of unsold F seats is equal to or greater than the number of Elites on this flight.

Update: just refreshed the PDA site, and F is sold out...the upgrade cleared and waitlist are the same, so my guess is a bunch of people took the lowball offer and jumped the line.

So what gives here??