I've been complaining about this screen issue since V26 was unleashed. Repitching notes, adding chords...almost anything you do and the screen gets cluttered until I force a redraw. It's really bad. After several back and forth emails with support, someone finally admitted this was a flaw in Finale, not a computer issue and that there were no plans to rectify the situation anytime soon. It really stinks - I wonder if anyone still works at Makemusic as a programmer to fix bugs? There hasn't been an update for a long time. I only use Finale now for older things I still need and will likely not ever upgrade again. After nearly 30 years it kills me, but Makemusic isn't meeting my needs. I've switched to a competitor which also has bugs, but at least there are live people I can talk to there.

Wow!  I thought I was going bonkers!  It drives me nuts.  How do you force a redraw?  Is that the same thing that I'm doing be scrolling left or right?  I write a lot of handbell music and with the thick chords it really is annoying!!!

CTRL-D. It's in the View menu.

Thank you!!!!  I was looking and couldn't find it - duh!   Again, thank you.

I've had this problem for some time too. I spend several months emailing files and comments back and forth with Make Music. MM could never get the effect to happen. This happened (I think but it's not documented; I was out of town during some of the times in question.) after some Microsoft Windows 10 update. I don't know which one.

MM analysts thought it was was probably a Microsoft issue. I could be or an issue with the screen driver or the computer manufacturer's firmware. This thread is the first that I have seen anyone but me with the problem. I have it on two HP computers (one laptop and one desktop running different monitor setups and different sub-versions of windows.) This is why I think it's Finale's problem but perhaps related to some timing problem with Windows.

I had a similar problem with printing several years ago; randomly, one of my network computers wouldn't print. By lots of experiming, I discovered that McAfee's free stuff (available from ATT) had a firewall that interfered with printing. When I disconnected the McAfee Firewall and used the Microsoft Firewall, things worked. (McAfee interfered  regardless of other settings. Their safe search didn't cause problems.)

Several other sites had problems including one university with 8 identical computers on a network; 7 worked and 1 failed like mine did. I'm guessing an interacting between Finale and Windows still.