yeah that is because the mount for the dash holder has different upper fairing mounting points for Gen 4 and Gen 5 hence the different parts. Gen 5 fairing mounting points are lower and diff angle to Gen 4
If you want a BSB/WSBK Gen 5 dash holder part I have one spare as I have Gen 4 fairings, I'm in Australia but happy to ship. $80 USD + whatever shipping costs, at a guess its prob around 40-50 USD. NOTE: it has a one dezus fastener per side for the top fairing.
its the top bit not the bottom bit, its made of fiberglass and has an extra bit on the front for a camera or other electronics etc.
For reference the bottom bit is an XXL carbon ramair duct