I attempted to see the 2019 calendar also as co-host to my daughters' account - but it will only allow Dec. 2019 to show from Months drop down. the Year drop down does'nt even show years past....starts from 2020 and goes forward.
I cant access the calendar either, but I have been able to get details of past bookings by looking under the Reservations tab, and looking under "all reservations". Hope that helps