I've noticed that
Login as the System Administrator (e.g. administrator).
Create a user without a home facility and without any user roles.
Go to the Administration → Users and search for a new user.
Click the "Roles" button next to the just-created user.
Select administrator (a user with roles that have Supervisory node empty) in the "Import Roles" modal and click the "Import Roles" button.
The roles in the "Supervision" tab without the supervisory node should be marked with an exclamation mark.
Click the "Save User Roles" button.
Again click the "Roles" button next to the just-created user.
then exclamation marks should appear anyway.