Spontaneous reordering of tracks when re-selecting instruments

I have a file here which was imported from MusicXML. As such, many of the instruments came across, but weren’t formally selected in Dorico. I’m working through them a few at a time as I clean up the notation and do further editing.

I’ve found that when I take one stave (player) and formally assign it to a Dorico instrument, Dorico then reorders all the tracks. It’s unpredictable, but annoying, because I already took the time to reorder the tracks in Dorico. See attached video.

The players are being re-ordered because I imagine your player sort order is set to “orchestral”. You can change the player sort order to “none”, which stops Dorico automatically re-ordering players and is a good idea if you’re sorting them manually, by clicking the Sort Players button at the bottom of the Players panel.