Need some more info on that. This sometimes happens to me when I play imported MIDI files but never when I created the file from scratch nor when I change playback to AU Instruments.

https://makemusic.zendesk.com/hc/en-us/community/posts/215729367-General-Discussion-House-Rules 

Yes, I have a workaround but, if we're not experiencing the same thing, it's unlikely to do you any good.

Thanks so much for getting back at this. Well, I honestly don’t have any more info on that. I created the file from scratch and it just started doing that. I have not done anything other than just write. 

Is this every file, old and new?

Thanks for the reply Mike. I guess because I only have this unique file. 

Ok, that's a start but you still haven't told us everything we need to know.

How exactly are you playing back? Please be precise beginning with MIDI or AU?

I’m sorry I didn’t understood your question in the beginning. I playback pressing play on the playback controls. And I’m using NotePerformer but the issue persists with Garritan. With MIDI is hard to tell because the sounds are bizarre LOL

The current release of Note Performer is 3.3.2. If not what you are running, contact Wallander for the latest update — I know there were MacOS 11 fixes in that release.

NP can be called directly from Finale or within the Aria Player. There are times when this makes a difference. Which are you doing?

Ivan Enrique Rodriguez Hope you solved your problem. If not, take a look here: https://makemusic.zendesk.com/hc/en-us/community/posts/360001218193-HP-playback-missing-notes-or-unwanted-staccato-notes