Versions 3.0 and higher don't place logs (or at least oak and spruce) at all, (they work fine on 2.5)

Are you sure, I couldn't replicate this. What version of printer and minecraft are you using? Can you link the schematic you are trying to build?

I think it's the same thing as "Printing without support directly in air" that is already in the known issues, since it works if there's a block underneath, sorry - didn't think of that before because blocks next to them were printing just fine, and it worked on 2.5. In case I am wrong and it is not that:
printer version: litematica-printer-1.19-3.2
mc version: 1.19.2
schematic: https://www.dropbox.com/scl/fi/lxpj7af6sq3ylciftod6q/obraz_2023-12-23_005014441_0_0.nbt

Closing as duplicate