Toggling the "Visible" property of a bar doesn't have any effect until the score is saved
Version: 3.0.5 - 58dd23d
OS: Linux Ubuntu 18.10 AMD64
If you select a bar, right click, and select bar properties, turning "Visible" on or off has no effect until you save the score (there's probably other things that trigger it too, but saving is the most repeatable I have found).
Video demonstrating it: https://vimeo.com/326217594