Dang that is rough. I had a wired xbox 360 controller and a usb microphone* wire that was not plugged in to the mic. I decided to remove both of those USB and wondrously sleep mode works. I also went to Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Power And added the DWORD 32 bit value AwayModeEnabled 0
Hopefully this gives someone some clues as to fixing it as not having a screensaver / sleep is a huge PITA and one of the many annoyances i've had with windows 11. This all happened after a windows update and previously i had all of these things plugged in with no issue, for years.