Do you have any paid Garritan product or just the ones that come with Finale?

Paid.  GPO5 + JABB

Just figured out what to do, and it works. dynamics markings were set to key velocity/value. I changed it Controller/Volume. Seems to have done the trick. Now to figure out how to get my accent mark to work  (under articulations that does not seem to have this option)

Not to even mention that I cannot get one KS function to work.  Baby steps......

Did you load instruments from the notation folder?

You shouldn't have to change the settings in dynamic markings. Human Playback should be doing that for you. Because some instruments use CC#1 for volume and other instruments use velocity.

I did. I'm at my wits end. Can't figure our why none of this working

Do your staves have names? (i.e., the violin staff is labelled violin and has a violin sample assigned to that staff?)

yes

Bottom line: Anything that is dependent on velocity does not work. The workaround with dynamic expression was to change it to volume controller, but this is not available from within the articulation menu for accents (only velocity).  As it is, I think my workaround is just that, and I must be doing something wrong. Willing to pay someone to look at my file to check what I've done incorrectly, including how to get ANY key switch to work

Interestingly, I set up a new file from scratch using setup wizard. Full Concert Band. Can't get it to work either. Not dynamic expressions or accents. Only on the piano staff the expressions work. Weird

I'm at a loss. It seems like it should be working by the things you tried. This is what my default Human Playback controls look like. Is there anything different about yours?

And this is what the playback tab on a "f" dynamic looks like for me. This dynamic affects winds, brass & strings (CC#1 volume) and Piano, Percussion instruments (Velocity based instruments)

Yup. Looks exactly the same. Didn't change any defaults. Frustrating. At this point I'd be happy just to at least get my accents (articulation) to work for now. Thanks SO much for caring. Appreciated

Update (found this somewhere)  When using space bar play, dynamics won't play. Use the controls to play will interpret the dynamics. But it brought up  new problem. Let say I have 4 bars, 2 half notes in each bar. Change dynamic marking on each bar. Before the new bar (dynamic) plays, the prior notes gets shortened. why?

I've not had that problem. One small thing I forgot to mention. I usually put an empty measure at the front of my score, before playback begins. This seems to help anything that Human Playback encounters in measure 1.