Bootable installer won't appear in Recovery on 2020 M1 Mac Mini
I have two bootable installers one for BigSur and and one for Monterey.
The Big Sur installer won't show up in recovery but the Monterey one does.
Both installers have been made following Apple instructions.
The USB for Big Sur was previously used as an installer for Mojave so I know the USB works as an installer.
Big Sur installer shows up in Disk Utility and the drive shows up as 'Install macOS Big Sur' on my desktop.
Any ideas what to do next ?
Mac mini, macOS 13.3