@GlinetteC  @ReyJohn_D @AileneA @KlentB @ReymondO 

I spoke with the programmer who writes the 3rd party solution which I'm using to convert QBO files from CSV files and he knew the answer off the top of his head. Please add this to your team's knowledge base.

from the programmer:

"You need to convert the CSV file again to a new QBO file (rather than trying to import the existing QBO again). My software generates unique transaction IDs every time you convert, so Quickbooks will not skip previously imported transactions as they will have different transaction IDs."

that's all – problem solved.  BOOM!  

I really do appreciate all the team's attempts at help, but seeing it just be this simple is illuminating.