Unable to boot from USB (new install)

Probably a silly error on my part.. seems simple but I'm stuck for some reason..

I was able to boot from my windows installer and get that side of things setup, Ive removed the drive with windows on, installed another ready for mac os and I'm trying to boot from the OpenCore usb.

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Have I missed something blatantly obvious? maybe I need another bios setting (although I was able to boot from windows10 EFI ok?)

Gigabyte Z390 Aorus Wifi Pro

Thanks!

https://preview.redd.it/8h5mx074lu151.png?width=1390&format=png&auto=webp&s=f333bffe5456831a3af8a36685574552d5875409

https://preview.redd.it/t6rlcbq2lu151.png?width=364&format=png&auto=webp&s=5d16a03c42b8ceeb4781b041abadd7f3d6e662b8

https://preview.redd.it/bp0jrso3lu151.png?width=448&format=png&auto=webp&s=87f08b9e66163cb6bb1be7bb9847ce92c94ae21d