Both of the two I noticed happened when buying two tickets together, and my partner’s ticket got the higher (correct) MQD while mine was shorted. In each case, I paid full price for partner’s ticket and used an e-credit for part of mine.

First example, flew JFK-LAX last month on a ticket that should have gotten $283 of MQD but it posted as $26. Same amount as previous poster, curiously!

Second example, I just flew LGA-DTW-HND on a Premium Select ticket that should have gotten about $2,250 MQD. The amount posted was $1,500, so I was shorted $750 MQD plus the associated redeemable miles. MQD on partner’s ticket posted correctly, so it was easy to see the discrepancy. On both tickets to Tokyo, the 50% bonus MQM on the Premium Select segment also didn’t post… so there was also that mistake.

I’d highly encourage everyone to start auditing their accounts, particularly if you make frequent use of ecredits to partial pay for tickets.