Something I noticed on Da Vinci 2.0

Hey folks Ive been setting here fighting with this printer for the past few hours not being able to print. Then I decided to jog the print bed all the way down to the bottom. Then whalla it starts back up. What I don't understand is why it seems to not do this on its own after you install new filament or clean print heads. But again Im starting  to think  that the print bed really needs to be at the bottom regardless before you start printing.You would think it would just start up at top and adjust itself? I guess not. Anyone else notice this?