My new M4 Mac Mini won't recognise Logitech Windows keyboard properly

I've just bought a new M4 Mac mini and everything is working really well – apart from my keyboard. I prefer to use Windows keyboards with a forward delete button, but the " and @ keys are the opposite way round from an Apple keyboard. With my previous Mac, it just asked you to go to the Keyboard section in System Settings, hit the key to the right of the shift key and it would immediately recognise the keyboard. When you do that with the M4 (which is running Sequoia 15.3.2, by the way) it comes up with a message which says "You have pressed a key on your Apple keyboard. Please press the keys on the keyboard that can‘t be identified.@ and refuses to identify the keyboard. In all other respects, apart from the @ and " keys, the keyboard is working fine.