Motion sensor behaviour if light in group already on

Hi! I am new to Philips Hue and Hue Essentials and loving it so far.
Currently I am planing to automate everything using the Hue motion sensors so that there will be no need for manual actions in most cases.

Today I setup a motion sensor in my living room that is setup as a zone containing 2 rooms.
I did notice that the motion sensor are only being triggered when all lights in this zone are turned off, if any light is already turned on the motion sensor doesn’t activate the scene for this zone.
Is this correct behaviour?
Is it also correct to assume that the lights (if already turned on) will not change to the “after sunset” scene when new motion is detected?