The link put on "registreer gratis" to hidden link for the content template login form is not saved.
The link refers to hidden link instead of hidden link.
Please refer to the video I have sent over wetransfer.
I watched the video but I can't see enough details to know what's going on, could I get access to the site to see?
Let me mark your next reply as private so that I can get log-in credentials from you—you may want to create a temporary admin user for me to use that you can later delete. And be sure to have a current backup of your site.
I suspect the issue is a caching problem, because when I visit the page hidden link while logged out, the Registreer gratis link is correct (see screenshot).
I'm struggling to see how the page is generated, inasmuch as the log-in form together with this link is inserted in a Content Template, but the account-pagina page neither uses this Content Template, nor inserts it.
I'm not sure what you've done here, but in any case the link is correct when I visit the page.