how to uncheck in a pdf
Re: unchecking radio buttons in fillable PDF. A toogle is a Check box, not a Radio button. You are using the wrong tool. You can change the box to a circle and it will look the same as the radio button, but provides the functionality you have requested.
In Acrobat set the value of the radio button group to Off. You can also group check boxes and change the symbol, this will allow one to uncheck a checked button.