Checkbox acceptance fields in backend

I create some checkbox acceptance fields in my WP website.
They are configured as “Not mandatory”, with visibility “Only me” and allow-custom-visibility = disabled (sorry for uncorrect translations, my site is in Italian).

If I change my user checkboxes in Frontend profile page the changes are correctly saved.
If I change them in Backend extended profile page the changes are not saved (checked checkboxes will not be unchecked and viceversa).

Frontend url: https://xxxxxxxxxxx.it/utenti/_MYUSER_/profile/edit/group/1/
Backend url: https://xxxxxxxxxxx.it/wp-admin/users.php?page=bp-profile-edit