Page jumps (anchors) don't jump – they load a new page

Hi

I’m trying to create anchor links to chapters/text inside my post.

I followed the instructions here:
https://en.forums.wordpress.com/topic/anchors?replies=7#post-234513
and here:
https://en.support.wordpress.com/splitting-content/page-jumps/

and I created the proper code in the html view, using the
Link code: VisibleTextLeadingToTarget
and the code for the Invisible target:

What happens is that the anchors work but they open a new page – opening it in the right place where I had put the anchor.
But what I want is them just to jump tp the anchor in the page – not to open a new tab and load again the whole page.

So, it looks like that even if I create the code just using as text for the href “#anchor”, wordpress changes it in “nameofwebsite.it/#anchor”, and this brings to the loading of a new page rather than just the jumping to the anchor in the same page already loaded.

If you want to see an example in my website, check this page:
https://www.ottimizzazione-pc.it/avvio-di-windows/rimuovere-tipi-di-carattere-essenziali-dalla-cartella-fonts-in-sicurezza/
The code I have added in the html view in wordpress is:
Metodo 1
but what I see in the source code once the page is loaded is
Metodo 1

Could you please help me to understand why wordpress is adding the whole url to the anchor?????

Thanks