However, as I said, when I save the user and return to the Edit Users page the list of users shows that the created user Login access is None.
I have just now narrowed down the problem / bug.
If you set Primary email address enabled to No then Login permissions display as None on the Edit Users page for that user. If set Primary email address enabled to Yes then Login permissions display as Email only
This is not how things previously functioned nor is it how it should be functioning according to the popup next to the Primary email address enabled option.
I have multiple email aliases in the Additional email addresses
You may want to select No instead if the user is being created for FTP access only, or if you have entered a different email address in the Additional email addresses field.