Page Links not rendering the hard coded link

I manage a website and have run into a weird problem.
The website https://www.thebutcherandbottle.com is the home page. When navigating to the catering page the page will not load unless the page is refreshed. The same goes for my events page and wen trying to navigate back to wp admin panel.
The url that does not load is as follows:
https://thebutcherandbottle.com/catering
once I refresh the page it loads perfectly with the following url:
https://thebutcherandbottle.com/catering/

Notice the forward slash on the second url. I have tried to change the link, but it is not updating in my system. The same goes for my events page and when I try to navigate back to the admin panel..

Any thoughts would be appreciated.
Cheers