Since updating to Monterey can't wake iMac with mouse or keyboard.

Since updating to Monterey I can't wake my iMac with mouse or keyboard. A response to an early similar post mentions that Sleeping is not necessary. But the Fusion Drive (my iMac is late 2015) is largely spinning drives so sleeping not only saves electricity but reduces the drive's total spin time. Is there any way to restore the wake function to the mouse or keyboard?