How to make markers NOT move?

I am scoring a video. In my DAW, I have like 30 empty measures in the beginning, as the music is supposed to start later in the video. No problem, since the DAW allows me to define the start and end of the project by dragging markers around… Or so I thought. When exporting MIDI, for some reason, it completely doesn’t respect the start and end markers, and exports those 30 measures in the MIDI file.

Whatever, I can just remove those 30 empty measures in Dorico when I make the score… Or so I thought… again. Removing those 30 empty measures in Dorico completely messes up the markers.

How on earth do I make it so markers don’t move around when I do this?

The markers in the Dorico project are relative to a specific time position (and not to a rhythmic position), so if you delete a bunch of bars, those time positions all change. I think if at all possible you should figure out how to avoid exporting the bars you don’t want to be part of the sequence from your DAW.