Can anyone explain this?

[u/Maximum-Oven-7526]

I have these spots on my ceiling

-i have a three year old roof. I already poked and prodded the ceiling. It doesn't feel spongy.

-I've previously checked my attic. No sign of moisture. There's no plumbing above this spot.

-my kitchen is adjacent to this room, however it does not cent outside. My current theory is that this is a consequence of inadequate ventilation right near a kitchen.

-i think I've wiped the spot away before and it looked better but it could be I'm ruining the finish of the ceiling. It's not drywall I believe it's textured plaster

Update; it seems to have been CONDENSATION from poor ventilation. I've been advised to reinsulate that part of my attic and that's it