The link URL should be generated dynamically, instead of storing the URL as an attribute.

Edit for clarity. To reproduce:

1. Create a page, name it something
2. Create a post
3. In the post insert a navigation block
4. In the block insert a link to the page you created
5. Save and publish
6. Check that your link links to the right page
7. Go to the pages list in WP Admin
8. Find your page and click the quick edit link that appears when you hover it
9. Copy the slug
10. Change the slug to lorem-ipsum
11. Save
12. Go to the page with the menu on the front end, refresh the page
13. Hover the link: the URL should be the old one, not lorem-ipsum
14. Clicking it should still take you to the correct page because WP handles redirects
15. Create a new page and publish it
16. Go to the pages list in WP Admin
17. Find your new page and click the quick edit that appears when you hover it
18. Replace the slug by pasting the one you copied earlier
19. Save
20. Go to the page with the menu on the front end, refresh the page
21. Hover the link: the URL should be the old one, not lorem-ipsum
22. Clicking it should take you to the wrong page because WP does not handle the redirect now