I have had something similar happen to me also when trying to upgrade both the outbound and inbound sectors of a flight within 24 hours of the outbound journey.

The agent helping me told me something about being able to issue the upgrade for the outbound immediately without re-issuing the ticket, but the inbound sector (because it was out of the 24/48 hour window) needed the whole ticket to be re-issued. They generally do not re-issue a ticket while sectors are being flown, so that's why my inbound sector showed as "Waitlist Confirmed" in my booking instead of upgraded. About a day after my arrival on the outbound flight (also YVR co-incidentally!), my inbound flight automatically was confirmed upgraded.

Just wanted to add in the data point as it's not really an "IT issue" but a system limitation, as it was explained to me.

I booked a last-min J seat from LHR-HKG departing in a couple of days (via my employer's travel agent) and wanted to upgrade to F.

I was unable to use any of the upgrade options online and called in. The agent told me that while there was 1 seat in F left for sale, it was not a redemption seat and thus they could not upgrade me by placing a bid or using Asia Miles (I was booked in D which is upgrade-eligible). She could not place me on the upgrade list either as it's within 48 hours.

However, she did advise me that I could ask the airport staff upon check-in to get an "instant upgrade" using Asia Miles on day of travel. I searched online and surprisingly found very little information about this - don't know if it's common practice. Wondering if folks here would know:
- Is this a guaranteed way to upgrade using Asia Miles or cash upon check-in (assuming the F seat remains open for sale)? Or at the discretion of the airport staff / inventory?
- How much $ or Asia Miles will this usually cost if available (I believe the upgrade award chart suggest 75000 miles for this route but wonder it'll be priced differently given last minute)

I put my emerald FF# from other carriers if it makes a difference (I do have enough Asia Miles in my Cathay account but only Green status).

You can always upgrade with cash at the airport, the $ amt is the difference between your fare basis and what's available in F (either A or F). It sometimes takes a moment or two for them to sort it out. I've done it at HKG (both landside and transit desk), SFO (back when SF had F), and LAX. Never an issue.

The upgrade cert situation, for me at least, became borderline useless sometimes in the last few years J->F.

How does CX deal with upgrading only one leg of a two-leg journey, where there is U availability only on one of the flights?

For example, if I have booked DXB-HKG-TYO which would typically be married segments, and only DXB-HKG has U availability, are they able to process the upgrade without upgrading HKG-TYO or is it only possible when both flights are available in U?

Grateful for the feedback and data points. Thanks!

you can get the DXB-HKG .

Thank you very much for the feedback!

Can confirm that the points were not automatically credited, and the chatbot agent said this happens from time to time.

Happened twice in a row to me though, so I wonder if it is a lot more frequent than it seems.