I'm not 100% sure either but I would wager that those have a sintered base (someone correct me otherwise). Just for argument's sake, let's say they do. When was the last time they got a stone grind? If you haven't been regularly waxing a sintered base, it can dry out and not easily accept wax until that dry top layer is removed. When getting said stone grind, make sure you get a structure pattern that is made for warmer, spring time conditions. Structure prevents suction from developing between your base and the melted snow. Normal winter structure has a fine pattern, spring structure will be deeper and more spaced out. Make sure you get this, it is just as important as selecting the right wax. Next step is obviously using a warm temperature hydrocarbon wax ( you can use low flouros but I don't think you'll honestly notice the difference).