RL Polo River Rock Paint Smells Bad in Humidity
If it didn't - I doubt it is the paint. If paint doesn't smell off when it is applied - once it is dry there is nothing left to smell bad - all of the liquids evaporate.
If you have an old house - it may just smell when it is damp. Our house is 160 yrs - it has all kinds of funky odors when it is damp.
You might want to check that you don't have any water leaks from roof or pipes near there. Also check the carpet
Where at in the house is the room or what room is it?