If you opened your windows and let all that coolness in, your house would cool off and no a/c.
What's the indoor temperature, especially near the thermostat?
The thermostat reads 75. It's in a hallway that doesn't get direct or even indirect sunlight.
It didn't kick on last night after the sun went down, but this morning it's running .
Mine is a touch-screen digital. See if you have a "more" setting at the bottom and keep hitting that until you get to the humidity setting. I set mine to 60% and that seems to work.