First clean your shoes properly and take care of them in such a way that they ate ready for a complete new season.
So see if there's any stitching gone, of something else needs to be repaired or replaced.
Then ner sure the shoes are dry.
Spray them from about 30 cm in a short way and let dry.
Try to spray in one spray the whole shoe.
Leave it to dry and have a new spray after about an hour, or as the package states.