Originally Posted by
Dave Noble
It is probably down to availability in booking classes.
e.g. the lowest booking class for one way PHX-PHL is V class - the lowest booking class for ZRH-PHL is different with V class ZRH-PHX being about $750 more than cheapest fare
Making a change for PHX-ZRH would be based on fare on best availability for PHX-PHL-ZRH
The 1st agent may have made a mistake or it could be that there was , say, a cancellation of a hold or booking and availability opened in a cheaper booking class for PHX-PHL-ZRH
On Expertflyer it showed 7 in all economy booking classes except Q and O showed 0.
Usually, I am use to chat agents making mistakes, not the twitter ones.