Please have a look at this little video: Its a bug, right?
This looks strange, but what you’re trying to do here isn’t useful. If you make a chord symbol appearance “Apply to All Roots” then you can’t control the appearance of the root - it’s the rest of the chord symbol that you can edit. Here you’re starting with a chord symbol that only has a root, and then trying to make it apply to all roots. That won’t do anything meaningful.
Well I try to move the flat up in relation to the root and I want that to happen to all roots. Isn’t that the right place to change this?
And I can’t trash any of the changes I have made.
In addition to the suggestions by @TonH and @Spielmann_M, you can control the position and size of the flat under Engraving Options > Chord Symbols > Design.
