Sleep command is actually putting the laptop into hibernation as opposed to sleep.
I have replaced my K270 keyboard with MX Keys, and the computer on / off button puts the laptop to sleep as expected. With the MX keys set to sleep as the button command for the "lock button" it's going into Hibernate instead.

Also when I turn of hibernate capability with "powercfg /hibernate off" the sleep functionality then doesn't work indicating it's sending a hibernate command as opposed to sleep command. Please can you fix this as it's a right pain.