Double bass is supposed to sound one octave lower than written, but so far it seems like it sounds two octaves lower than written in Dorico. The lowest note that will play back for me is the C on the second space of the bass clef, which sounds like the C two ledger lines below the staff on the C extension.
We’re aware of this (internal ref: STEAM-4496). Please let us know if you spot any other instruments sounding too low or high.
Would be nice if we could see a list of known bugs, to avoid report duplication.