After enjoying my BK10 bluetooth keyboard for over 1 year, it suddenly stopped going in to low power mode after 30 minutes of inactivity.  Not and end of the world issue, but annoyingnone the less, as it results in much shorter usage between charges.

I'm connected to a MacBook Pro running macOS Monterey (12.6).

I have of course already tried rebooting the Mac, disconnecting the keyboard and reconnecting, and also removing the connection from the Bluetooth Preferences and re-adding the keyboard. None of this resulted in the low power mode working still.

Have I inadvertently hit some crazy combination of keys to turn off this setting?

Thank you in advance for any useful suggestions.