I created a form where author user should be able to edit his own entry. By default a button is appearing at the top of the form, but click on that button will return to the homepage. So I think the generated link is wrong ..
To create an edit button, I make a free button with the following settings:
Label: leave blank
Label Icon: replace - edit
Button: button
Link: form - click "+" and select the form that the button will edit
Show Alternative: hide
Storage: none