Directory Services -> Active Directory Domain Account Name and Password are not mandatory and should be
The Active Directory Domain Account name and Domain Account Password are supposed to be mandatory fields.
Neither field is mandatory in the Legacy UI or the webui.
Both fields should be mandatory.
Leave the fields blank and click Save
Only the Domain Name field gives the error "This field is required" error
Tab through each field past the Domain Account Password field
Only the Domain Name field turns red and gives the mandatory field asterisk.
See attached screenshots