That sounds like a UI bug or conflicting plugin; if the box isn’t working you won’t know if the auto-add-to-group function is working (I presume it does).
Anyhow, try safe mode (/safe-mode) and turn off customizations and try adding the domain.
That sounds like a UI bug or conflicting plugin; if the box isn’t working you won’t know if the auto-add-to-group function is working (I presume it does).
Anyhow, try safe mode (/safe-mode) and turn off customizations and try adding the domain.