Never mind! I found out by accident that I need to also bind it again in the "CH-47 Gunners" options in addition to the "CH-47" Options. Basically I had to duplicate the binding in 2 separate sections.
I have it working now, What I find interesting is that I selected that entire "Keyboard" Column multiple times since yesterday, and once selected, I clicked on " reset Category to Default" and it did NOT place a "TAB" keybinding in the "Multiplayer Chat-Mode All" So I didnt think I had to ADD the "TAB" key to that line because it didnt install it there by default, and still doesnt? So I ADDED it manually,, ,now all is well. Thanks for the lead!
Fakum's post in Cant Switch Seat Positions With HAT Switch Properly? was marked as the answer