The short story is that I signed a form that I created and realized after signing and saving over the original file that I missed a date field. I go to clear the signature from the signature panel and there is no option. I signed with the drop down list signatures and "stamped" the signature over the signature field. In the older Adobe acrobat I used, I was able to go to the signatures panel and select "clear all signatures" when I wanted to regain editability but that field is currently greyed out in this version (along with all other signature panel options). I ended up deleting the signature from the "Edit PDF" tool but even after deleting it and editing the form after, all form fields remain un-editable, even in the "fill & sign" tool. I have recorded the screen to show exactly what is going on. You will see that when the "edit form" tool is open the fields are visable but when "preview" button is pressed the fields are no longer there.
Your fields are set to read-only (can be seen in the properties of both fields you showed them of in your video). Thus, the user may not change the value of the field. Any associated widget annotations will not interact with the user; that is, they will not respond to mouse clicks or change their appearance in response to mouse motions.
Have you probably had originally configured the signature field to lock all those fields or even the whole document? In that case that read-only flag will be set for all those fields during signing as a side effect, and clearing the value from the signature field does not undo this.