Strange string attached to my URL

Hello,

I hope someone can help me with the following problem.
I am using a template that offers 3 boxes on the frontage from where the link takes you to the page.
The first two boxes behave normal and as expected, however the 3rd one is automatically attaching a strange string behind the url, causing it to turn into a 404 page. what is going on with my third image box on the frontage?

The address is
https://www.lokaal-aanbod.nl

clicking on the 3rd box in the frontpage takes you to a default error page. The URL shows:
https://www.lokaal-aanbod.nl/aanbod-opvoeders/ ? %20%E2%80%8E

could you tell me how to fix this? I tried several links to other pages, same result?

Thanks in advance