Problem with landingpages en navigation menu

Hello everyone,

I am having a little trouble with some of my landing pages and dont know how to fix this. this is my website https://paintstore.be and when you use the navigation menu its not always going to the right page even though the url is changing. One example is the page beits which you can find in “houtbescherming” and then “beits” the url changes but it does not go to the requested page. The website crawl from my google merchant center also has adopted a lot of wrong landing pages for my products i dont know if this is related.

Thanks in advance!

The page I need help with: [log in to see the link]