Hi Peter, Firefox has a preference to shorten all cookie expiration dates to "session only." (It is the checkbox in this image: https://user-media-prod-cdn.itsre-sumo.mozilla.net/uploads/gallery/images/2020-01-12-14-59-10-e3453e.png ) Firefox also has a dialog box to add site exceptions (on that same row to the right of the checkbox in the above image). You also can add site exceptions while visiting a site). Firefox doesn't have any method to preserve only a single cookie instead of all cookies for a single site. You could consider using an add-on for that.