Here’s a quick one. Have you ever encountered this issue in Sibelius, where a cautionary time signature is uncomfortably hanging outside the edge of the page margin?
You might think that resetting note spacing would help, but it doesn’t.
I’m not sure of the cause of this problem, but a solution I’ve found is to select the barline and apply a system break (Layout > Breaks > System Break, or the Return keyboard shortcut).
Make into System and Lock Format also seem to work.