How can I edit an email address on JotForm sheets?

To clarify you want to edit one entry (i.e. email address) in the submission present in JotForm Sheets page. Is that correct?

If yes, you can directly edit the entry as shown below:

Please try and let us know the update.

That is what I've been trying to do.  It will let me click in the Email box and highlight text blue, but it is not letting me backspace/delete/type anything to correct it.

We suggest editing it through Edit Entry option then resubmit the form after changing the field value. This is how form data are normally edited.