Site title field does not change

Hello!
As the title says, the site name field does not change.
Although pressing “save” indicates that it was saved correctly, it does not.
I am a site administrator so it is not a permission issue.
to try; create an ACF field to change the title and don’t save it either.

what is curious is that the “Site tagline” saves it just like the logo.

thx!
regards