Ok, I just figured out the solution. I was creating a new invoice by *copying* the invoice that I had changed and hoping QB would auto # the new invoice created from the copy with the higher # but it kept reverting to the old #s. When I tried creating a brand new invoice - rather than making a copy of the existing one with the invoice # I had to manually change - it worked. QB auto-generated an invoice # that was 1 higher than the last # (1623) that i manually entered. I hope this helps someone having this issue!