Hi Hugo,
Upon checking, the title in the link you provided seems to be created through a Block Element.
You can check if it is indeed from a Block Element by hovering on Elements in the admin dashboard while viewing the page as such: https://share.getcloudapp.com/v1uO4m9q
If it is from a Block Element, the disable content title function wouldn’t work. That functionality works for the default title. What you can do is set the Block Element to draft, or modify its display rules to make it display only in your preferred locations.
Kindly let us know how it goes.