I have 3 computers--2 at my home office, one in my classroom (I teach in Fresno Unified School District). Sync is lightening fast between my 2 home computers. But when I save a file in Sync folder on my home computer, it does not appear on my classroom computer. I CAN download it, after several clicks, on my school computer, but it should be right there in my sync folder at school. Any advice to get Sync synching?