Hello community,
PROLOGUE
I am working on a reconstruction of a silent movie chamber orchestra score with a 1922 manuscript but the film is not fully reconstructed yet.
The manuscript has lot’s of sync markers in it, as it was intended to be played live by an orchestra. The film has some lost and destroyed scenes so the score needs to be edited afterwards.
I copied all the markers of the manuscript using Doricos marker functionality by setting the playhead to the desired position and pressing my CTRL+SHIFT+M - Now i have around 250 little text boxes.
I now need to adjust some of them, but when i drag markers to a different position (in Write mode) and ALL subsequent markers change their position relative to it.
This is driving me nuts!
Is this behaviour intended? Do i have singular control over them?
Any ideas for me? Do i really have to rebuild all Markers with SHIFT+X Text boxes?
Just an idea - what if you click on a marker and use alt-arrow to move it, by the rhythmic grid?
Dorico also recalculates all Markers, makes no difference.
I came to the conclusion, that Markers are not the right tool for my needs. Far too sensible and loaded with unpredictable consequences.
So, i bite the bullet an reconstruct each and every of the 280 markers as textboxes 
I’ve never worked with markers but I have read the Version History and I think there’s a better way of doing this.
Read pages 79-86. Then go away, make coffee, come back and read page 83 again, carefully.
If you drag or nudge a marker, it will recalculate the tempo at the position of the previous marker, which will have a knock-on effect. Markers are bound to time, not to rhythmic positions in the score. You can edit the position of a marker without adjusting the tempo and therefore the position of all other markers by using the Video panel in Write mode, where you can adjust the time position for each marker.