Personal to Sleep Focus

I created a shortcut and automation to read my shift schedule and set the work focus as required. If I'm not working it defaults to personal focus. I've noticed though that once the scheduled sleep comes around the phone goes into what seems like sleep focus but is actually still in personnel focus ( some notifications come through) unless I manually select it into sleep focus. Has anyone out there run into this, or understand why sleep focus won't kick in automatically according to the pre-set sleep schedule?