HELP! 'list your business' page redirecting to admin log-in page

Hi

I have a page within my website “list your business” that shows the available listings – accessible via the navigation bar top left (suppliers area) – however, it is redirecting my customers to the log-in page. It is the only page that does this?!

https://www.theglasgowgirlsweddingguide.com/

Can anyone advise why or tell me how to fix this?!

Thanks!