I've had this happen twice now so I don't think its an accident. I fly the same sector (US->DOH-Asia). sometimes I need to change my return journey dates.

What I've noticed is whenever I do this, the flights offered always have only 1 cheap option, and that one has a huge layover (16hr-20hr). This is NOT the case when you book the original flight, when they are all the same price (even the ones with a 3hr layover). But when changing, the others are ~$500 or more extra.

What this means is you pick the one with the long layover, and then QR literally offers nothing - no STPC, no meal vouchers, nothing. You could book a discounted hotel but they will not provide transfers etc.

I'm not saying any of this is technically illegal or wrong, its their choice. But I've never had this happen with other premium airlines and I've now been burnt twice by this. Also its not like I'm changing flights close to the return date.

Maybe its just a coincidence but I'm very disinclined to believe that,