The link I have created is in my Sydney Child: Theme Footer (footer.php) so I do not know if it overwrote something in there. Also the page can be edited in Elementor shen I go to Pages and open in there and I can edit it. Also, after I visit this subpage, that appears all white (no content), and than try to go to my start page (domain name) the start page also shows all white (no content).
Thank you for your help.
Best regards & Best wishes for the the New year to all of you,