Personally I do not like AF strawberry and I had the same problem as you. Not sure about our techniques but I think it's just AF strawberry in general. It has a creamy smell and not a great strawberry imo. My session with AF strawberry for the first time was horrible and it almost made me give up hookah forever haha.
But you can fix that burnt problem by keeping a good space between the foil and shisha. Don't pack it too tight, just sprinkle it in and keep a good distance between the foil and shisha and you'll be straight. Hope that helps.