Hi, you should start from the very beginning and searching for flight in Private mode on your computer (Ctrl+Shift+N) so that cookies won’t be stored during the search. Otherwise cookies could be stored on your computer and prices might rise after a while. Also take a look at flights search engine like https://tripsta.co.uk/: it compares thousands of flights from multiple sources to find the best deals. I have been using it all the time and it works great for me