If you play the attached Dorico file as is, you’ll hear the dynamic noticeably increase at Bar3(three) and then drops back again at Bar4(four). Having experimented, if you remove the notes in just the “left hand” in Bar2(two), the dynamics stay as they should.
Should this end up being a bug, the coding Elves might want to know that I engraved the “right hand” of Bar2(two) manually and copy/pasted that into Bar3(three).
Your thoughts people?
(Bar numbers in words and numbers so you know I’m not making typos (o:)
I’ve not tried playing back your project (I’m in a meeting right now) but try changing the options on the Dynamics page of Playback Options for polyphonic voice balancing and/or pitch contour emphasis, and see what happens. If you input the music using a MIDI keyboard in real-time or via MIDI import, there may be saved velocities on the notes: try Play > Reset Playback Overrides.