There was an entry for "freecadweb.org" with three cookies but no data, as well as the "forum.freecadweb.org" that you can see is still there. It said three cookies and no data, I deleted them and have since been back to the site and there is now nothing listed under "freecadweb.org".
I went to the settings and then clicked on "manage data" which takes you to this below, as you can see only the forum entry is there now, but at first there was an almost identical other line there that was just "freecadweb.or" without "forum" but had the same 3 cookies and no data. Did our web site every install cookies? This system was a clean install of Kubuntu 18.04 late last year, i.e. 2018.
Anyway for me it is fixed...others on Firefox could do as I or others have.