I have seen a job with walk in pits and no hw access at bottom landing. Still used hnb with break out board for unused switch. They just permanently jumped back making contacts permanently on break out boards.
FWIA does have built in repeater, and has to have firmware V4R1 to work reliably. If VER command show V0 firmware on FWIA, then you can warranty this board. Make sure you check with cars in group isolated from each other. VER command on car 2 may show firmware for FWIA from car 1, I had this happen.
Car Generic should be at minimum V4R2F, or V5R0P if emax enabled. I have seen issues like this with older software, but have these have been fixed in last couple of years. It sounds like you are adjusting so I would be surprised if you have older software, but sometimes job materials sit around awhile because of construction delays.