Door closed sensor malfunction during Car Wash

Was the car in car wash mode? (don't know if that affects anything as I don't use automatic carwashes, trying to minimize scratches)

Yes

Sometimes, particularly in cold climate, the door handle may get frozen and be open enough to have it constantly be getting a "open" command from the physical handle, try opening + closing the handle a few times, spray silicone WD40 into the springs (where the handle pivots). If that's not it and you don't see anything blocking the inside from latching, I'd request service.

The handle seems free. I believe it may be the latch/sensor. Is it OK to wd40 that?

It needs to be the silicone version of wd40 specifically (for the inside of the handle, not sure about the latch)

a rental that I had the opposite issue with a model 3 it thought the door was always closed so the window would drop for half a second when you pushed the exit button then Go back up hitting the trim if you tried to close the door. With the internet and a spare I had on hand it was fixed by replacing the courtesy light at the bottom of the door.

Do you have aftermarket puddle lights?

Negative

When you unplug the puddle light the door thinks it's closed. I suggest you replace the door puddle lights with the cheap tesla logo ones on amazon like I did. That's how I know disconnecting the light makes the window go up and down like the door is closed.

Update: the problem seemed to just go away. Must have dried out. Thank you all!