Select a number of midi tracks and open up Score settings → staff → main property page.
Checking whether all staff names have been filled in correctly.
When I click through the list of selected tracks in the left pane the tracks that do not have staff names filled in (no long and no short description) still show a (random?) value from the ones that do have those fields filled in.
Question is now: do other properties show wrong values too?
Another usability thing in this particular UI is that when you change the the (long)staff name text box the “apply” button does not enable right away, you have to click somewhere else to enable it. Please handle that text changed event or something like a normal program would.