Shortcodes not working as breadcrumb menu

I’ve installed the plug in and am using it with buttons created with maxbuttons.

The buttons show up on my menu but there’s a problem.

My home page is https://www.teachcircusinschools.co.uk

I have only 3 pages on my site.

If I click from Home to the first page, Primary. All is okay but, if I then try to go to another page, for example home this is where the button tries to send me:

https://teachcircusinschools.co.uk/primary-schools/www.teachcircusinschools.co.uk

So rather than reopening just https://teachcircusinschools.co.uk

It’s retaining the link for the page I am on and bolting onto it the requested page?

Do you know why?