Problem using highlight option

Hello everyone, I have a problem while using highlight option. I am reading a book on pdf format that doesn't have text recognition, and I highlight some parts of the text with colors (like if was painting on it). At some point, adobe started by default, each time I highlighted a line, to reset by default the option with "selection". I have each time to click again on "highlight" and bu the end it is time consuming. Do you know how I could fix it?