If you are running Windows 11 on an incompatible machine, then you are at the end of the road as far as the Insider Preview Programme goes. For some reason, Microsoft is informing people that they must revert their devices to Windows 10. There is a workaround, albeit with limitations.
https://www.notebookcheck.net/Microsoft-has-started-booting-incompatible-devices-from-the-Windows-11-Insider-Preview-Programme.558020.0.html