Also when loading directly into the bottom chamber is there supposed to be a screen in the bottom? Mine is missing if so but I can add one.
Also why is that top chamber my mom was using there? Is it really for convection vaping or what?
The cans don't work well for herbs and have never worked well with wax/oils for me either.
Yes there should be a screen on the bottom of the chamber. My understanding is that the top chamber was originally designed to add other herbs in the top along with your bud in the bottom chamber to add different flavors to your herb, I believe the idea was pretty much a failure in practical use.
Like KidFated I still have lots of respect for my og Davinci, works great still although after near 3 years use, the batteries are now only good for 3 or 3 1/2 sessions instead of the 5 sessions when new but after a pound or so of bud being vaped in it over the years I'd say it's served me well.
(My very very first DV from back when they first started selling 'em was gifted to someone within weeks of me getting it and it still works great, tried to trade back with other vapes but the owner loves the higher temp in the units first released by Davinci )