This tutorial needs updating, or at least adding a caveat to say that it is out of date
If you want to know why, I have posted this question on the Strapi Discord
Basically, Strapi v4 no longer allows you to add more than 2 nested levels of components (you can’t bypass this by editing the schemas directly, which was possible before)
My solution was to just duplicate the attributes for the “Link” component instead of attaching the “Link” component. More detail in Discord post