Thank you for sharing this. I too have noticed that on AA the SWU option doesn't show up all the time. For instance, I was considering a MIA to MAD flight on Oct 6th (AA68). Right now EF is showing C1 but when I look on AA.com it doesn't have the SWU as an option. A few days ago it was C4 and even then it wasn't an option. Ultimately, I decided not to book it because it didn't work best with my schedule.

I think the biggest thing to take away from this (for me) is to call before booking and just do it while on the phone. It's getting harder and harder to use and SWU in the first place so this is even more concerning.

Edit: I actually realized I wasn't logged in. When I logged in and searched it shows the SWU available. Still a bit concerning but at least I know I need to be logged in to see SWUs on AA.

You need to check the availability for the whole journey

The segment may have availabilty as a standalone sector, but if you are connecting, the availability may not be there

This is interesting because when I search my example for the MIA to MAD flight as a single segment I show SWU available. When I search for my full itinerary (where I'm essentially just connecting in MIA) it does not show it available. In the past the SWU option on AA.com would show which segments were available. I know you could waitlist for the segment one cared about (typically the international portion) and if that came available you'd get the upgrade and then waitlisted for the rest - presumably the domestic segment. Does an SWU have to be available on ALL segments to process?

What is the full journey?

This specific one was ABQ - DFW - MIA - MAD. Probably going to choose to just go DFW to MAD because I don't feel an extra segment is worth the confirmed SWU from MIA but found it interesting nonetheless.

Normally I'm coming from PHX but have an event with the in-laws in ABQ I can't get out of. But that is the perfect example. If I was doing PHX to MIA why can't you book and use the SWU on just the MIA to MAD part? I know I've done this in the past.

I missed the overnight and had the wrong flight when I checked PHX-MAD

Availability can vary on sectors depending on where you are coming from or going to with connections

A-B may have U1 C1
A-C via B might show U0 C00 for the same A-B flight

For ABQ-MIA on 6/10/19 , AA2335 connecting to AA2550 connecting to AA68 does show C1 for DFW-MIA and MIA-MAD , so surprised if unable to upgrade

C is not being used here as a generic term for business class. It is the specific inventory bucket used by AA for Systemwide Upgrades to business or domestic first.

I've had this type of ghost C inventory issue as well. Fortunately it was to my benefit as the international leg was able to be cleared immediately (LAX-HKG) but I had to settle with the waitlist for the SFO-LAX leg. Yes... No brainer and not worth the fuss from me. In the end I ended up clearing 2 days before the trip.

Both EF and aa.com show the entire route available for SWU's. It's a bug or worse they're holding back inventory.

Perhaps give another region's reservation desk a call and see if it can do it. Australian phone number would be my next try

I bet the glitch is because of the ORD-DCA leg. Did you ask them to just confirm the CUN-ORD part (which actually has C)?

Edit: I might have misread your original post. Are you saying the CUN-ORD leg on the 787 has already cleared and this is just about the short ORD-DCA leg that you will probably clear as CK for anyways?

That's correct. I realize I'm being overly pedantic here, and the upgrade will eventually clear. I just don't understand why both aa.com and EF say there's availability and no one at AA can see it nor cares to figure out why the disconnect.