Not booting without usb

I have set up my Hack with MacOS Big Sur and it mostly works fine. But I can't manage to boot without the usb. It wouldn't boot using the drive the system is installed. I've already copied the existing folder from the USB to the existing folder in macOS but it still doesn't work. Could it be a problem with the bios settings? Also a small problem I have is the scroll wheel of my mouse scrolls in the opposite direction. I would appreciate any help 🙏