Customized barline spans not always overriden when extending staff barline span
3.1-beta
This is related to #287613: Set to staff default only affects first selected barline
Create the score from the Classical Orchestra as in #287613: Set to staff default only affects first selected barline
Select the first 2 measures of 3 consecutive instruments, like the Flute, oboe and Clarinet.
Right click the barline and chose Select all similar items in Range selection.
Remove the check from "Span to next staff"
Click "Set as staff default"
As in the other bug report, the barlines are only shortened in the top staff (Flute)
Double click a barline on the flute and drag it below the clarinet. All of the barlines are connected except the barline you previously selected that should extend from the Oboe to the Clarinet. The way to fix this is to select the short barline and check "Span to next staff"
Comments
Hmm, for me it's working, but I suspect I'm misunderstanding something about the instructions because I don't know what "added instrument" in the title refers to. Here's what I see on the final step:
I wrote the title and discovered some new info and forgot to change the title. Here's my animated GIF.
Ah, I think you are dragging all the way to the bassoon staff where I was releasing just below the clarinet staff.
Anyhow, the mystery to me is why the oboe and clarinet staves are acting differently here - either both should preserve their custom span status or neither should. But I'm sure once I dive in I'll find the explanation.