Percussion barlines disjointed when spanning multiple staves with one staff line.
The picture is from the attached file. When barlines on a staff with a single barline are extended, they look disjointed. Making the staff have 2 lines is sufficient to make the extended barlines look like a single line.
In the attached file, change any of the staves to 2 or more lines, and you will see the improved lines for that staff.
I'm not calling it a regression because I noticed this back in earlier 3.x versions.