Hi davidb73512378 ,
Would like to inform that if you are trying to change the text in fields of the form then need to check whether the fields are locked or not. If they are locked then it wouldn't be possible to edit it .
If you are trying to change the text of the form & facing the issue while doing this then would request you to please share the screen shot of the Document properties.
May be that the form fields are set as read-only.