Permalink suddenly changed

Hey

The link in the text has suddenly changed. He added things.
How can I change that again? Because there are a lot of links.
It seems that the permalink itself has changed.
http://www.samenbeterthuis.nl/verplaatsen/opstaan-en-zitten-stoel/voor-in-de-stoel-gaan-zitten/ Good link wrong page
http://www.samenbeterthuis.nl/voor-in-de-stoel-gaan-zitten/ Good page wrong link

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