They are supposed to mark bookings as scheduled in the first instance and once the booking has happened mark it as confirmed. Vast majority of them seem to ignore the scheduled marker and go straight to confirmed. This can be irritating for punter as he will constantly get a pop-up every time he logs into AW telling him he has outstanding feedback to leave (feedback for a booking that's not until next week....).
No idea why it shows as scheduled on app and not on PC? Are you looking in right place - are you looking at "All Correspondence" under Emails & Bookings tab and opening up the relevant line?
Irrespective of AW booking system it's best to keep cool and ambivalent until you have some sort of meaningful contact on morning of booking, before then it's futile to think you have a 100% cast iron booking. Also, line up some alternative ladies you may wish to call at short notice if your original target goes AWOL - best not to have all your eggs in one basket.