You could also go into your BIOS and make sure Secure Boot is actually enabled. Another option is to check for a BIOS update from Lenovo that might add the proper Windows 11 support.
Agreed. I had the same problem. Even after enabling those, I had to change my disk partition to GPT before the installer would finally take it. Good luck!
This happened to me. I ended up using the official Media Creation Tool but selecting the "This PC" option for the upgrade, and it finally pushed through. Let me know if that works.