It depends on what your lighting periods look like for the two respective modes. From what I can tell, there is something off with your device table. Your table should have the Porch (Hue Group) in it with both the ACT and OFF boxes checked. Then, if you leave the Means to Activate/Turn Off the same, it should work fine. I run a couple of lights like this and have no issues.
You can ignore some stuff, but the big thing is that you do not need lighting periods at all with this. Get rid of them, and just leave your Means to Activate be Mode is Evening and your Means to turn off be Mode is Night. It will work exactly how you want just like mine do. The nightlights turn on when Mode goes to Overnight and Turn off when Mode becomes Sunrise-Sunset (or a morning scene switches on).
Yes. That should work the way you want it to. When Mode becomes Evening, it will Turn on this Room Lighting instance. Because the Porch (Hue Group) has the ACT box checked, it will turn on with Room Lighting. When Mode becomes Night, it will turn off this room lighting. With the OFF boxed check, it will turn off the Porch (Hue Group) when Room lighting turns off.
Now if you wanted to keep the original, there was an option that needed to be selected. You wanted to select Adjust Lights on Mode changes under Additional Options in the Means to Activate Lights. Room Lighting does not automatically progress from one mode to the next without this option selected.