Here's an interesting one.  I've used the plug in JW Staff Polyphony to swap music from one staff to another (this functionality should actually be built into finale, but that's another issue altogether) when working on arrangements.  For example, I get called to make playable parts for some composers out of their playing for string sections.  After explode, it's a mess (an actual smart explode that follows ties would be a godsend).  I use swap to move music from one staff to another to get the ties to line up that explode messed up.  

I've been using this method forever with no issues and I'm in the middle of trying to get a project done for someone.  The last two days it's worked as expected.  Yesterday it started behaving screwed up.  When I swap music from one staff to another, Finale insists on making the clefs "follow" the music to the opposite staves. 

I have not touched a single thing in Finale other than working on music. I cannot, for the life of me, understand what changed that's now making Finale behave this way.  I've tried everything - "Hide cautionary clefs, keys, and time signatures" with the measure tool as well as "Display courtesy clef at the end of staff system" in document options.  Nothing works.  I have no idea why Finale has suddenly decided to copy the clef with the music.  

Can anyone offer any suggestion as to why this started happening and what would make Finale do this?  

Here's a screenshot of what happens when I swap music from one violin to viola:

https://i.imgur.com/sR0579l.png