It appears that Dorico 6.2.10 doesn’t currently support showing the hidden instrument label signpost when a system break occurs and the transition has already taken place on the following system (specifically when using the option ‘Instrument transition position: After last note in old instrument’).
See the attached file: if you click ‘Hidden’ in the properties, the instrument change warning label disappears but no signpost appears. This makes it impossible to select the element again.
Or am I missing something?
InstrumentChanges-Signpost.dorico (1.3 MB)