Thanks, that did it. I had previously loaded Setup Defaults in BIOS before and after the BIOS update, saved and exited then tried again, but nothing changed. Loading Setup Defaults usually accomplishes the same thing but apparently not on this BIOS.
It also caused a complete rebalance of PCI resources the USB 3.0 controller is being detected again as a 'new' device even though it was already installed with the correct drivers. Anyway it's all working now so thanks for that.