This is vanishingly unlikely. I've worked on plenty of digital pricing models, and never once was there the slightest whiff of a suggestion -- even from management consultants who might be expect to espouse such views -- that the same item should cost more based on which device is used to purchase it. Ironically, it's more likely to be random (Amazon has tried this, to gather hard data on what customers are actually willing to pay, though no airline has to my knowledge) fluctuation than it is to be device-based.

Far more likely to be a bug, or perhaps some old inventory data loaded into the app.