> Bought some flights on Scandinavian Air through Google Flights that included multiple checked bags for my wife and I about a year ago. Upon arrival at the airport in Gothenburg, they were very insistent we hadn't paid for bags and had to pay the exorbitant fees for checking bags on the spot.

Something like this had happened to me often enough that I no longer purchase anything through an intermediary when traveling. Flights, directly through the airline. Hotels, directly through the hotel. Theme park, directly through the park. Is it convenient to make reservations and/or pay in person on-site? On-site it is.

The occasional discounts just aren't worth the clusterfsck it becomes when there's any kind of misunderstanding or miscommunication.