in firefox, click on the shield in the top left of the address bar and turn off tracking protection for ukmonster.co.uk, the shield should appear with line through it.
if that doesn't work try clicking on the 'burger' menu (3 lines), choose 'privacy & security' and click the 'manage data' button. search for "ukmonster", double-check the results only relate to ukmonster.co.uk,
www.ukomnster.co.uk etc. (I can't imagine anything else will show up) and hit the 'remove all shown' button followed by 'save changes'