Mac bringhtness
When i put the mac to sleep it decreases the brightness to 50% automatically is a Monterey 12.3.1 bug?
MacBook Pro 13″, macOS 13.2
It is a setting in the System Settings somewhere. Open the System Settings app and search for "battery dim" and you will get a result the quickest since Apple has moved the items around to all new areas for some of them.
In the "Display" System Settings, click the "Advanced" button and towards the bottom of the pop-up window under "Battery & Energy" which has a toggle for "dimming the display on battery". Uncheck it and you should be Ok, but your laptop will use more power when using the battery.