Inspiron 7591 won't sleep or shut down in Windows 11

My Inspiron laptop won't shut down using the start menu power option. It immediately restarts. It also won't sleep or hibernate and constantly kills the battery. It will shut down with the 'shutdown -s' command at a command prompt with administrator privileges.

This happened once or twice in Windows 10 but I was able to fix it by reinstalling Windows. It was a pain but it worked and it's easy to restore the few apps I use, and everything I care about is on OneDrive.

I've since upgraded to Windows 11. Now the problem recurred but I can't correct it by resetting Windows.

I ran powercfg a couple weeks ago to see what was using the battery. I forgot exactly but I think it's the Intel SST driver that's mentioned in relation to problems upgrading to Windows 11. The resolution to that is upgrading the driver but the driver version I have is newer than the one cited in the Windows 10 problem resolution threads. If I try to update it from Device Manager, Windows tells me I have the latest.

Does anyone have any suggestions for resolution or troubleshooting steps?

Thanks