Just a few weeks ago, I searched flights for a family member going to Vegas on my laptop. I got price A. A couple of hours later when I was on the phone with the family member, they were seeing price A on his computer, but I was seeing a price about $90 more than price A on my computer, simultaneously. I immediately opened in “incognito” browser in Chrome (Control + Shift + N), and ran the search again. Now the price, which was $90 per ticket higher seconds before, was back to the original price, for the exact same flights.