So when I go to my car this morning (2021 Advanced w/o remote start)) all 4 windows were about 1/2 open. I definitely closed all the windows last time I had used the car. Thoughts on how this happened and how to prevent this from happening again?

 

By any chance, did you press twice the unlock button on your remote and held it for a few seconds?
That would open all 4 windows and the moonroof automatically by itself remotely

 

If the remote was in your pocket, the unlock button might have been pressed and held.

That has happened to me in a few cars.

 

This can definitely be attributed to unintentional remote activation

 

It only happened to me once but it was the worst possible time. Walking from the supermarket to the car in the pouring rain, I tried to open the tailgate so it would be open by the time I got to the car. As I approached the car, every window AND THE PANO ROOF was in the process of opening all the way. What a mess.

 

Very odd, today I found my car (in my garage) with the tailgate open, all windows down, pano part open. 1st time in two years that's happened!
Coincidence? ('19 aspec)

 

I had this issue with my previous Acura's and went with a fob covers for our MDX and RLX. I also got the fob covers in different colors so I can tell my key apart from the wife's at a glance.

My fobs are the interior colors (ebony/graystone) of our vehicles and the wife's fobs are the exterior colors (red/blue):

 

Are those OEM FOB covers or where did you get them?

 

Make for the larger Acura fobs with remote start for MDX and RLX
Amazon, $13:

 

I use these. Not available in as many colors but they're specifically made for Acura fobs.

 

Yes definitely key fob buttons being pressed in your pocket. Happened to me all the time before I finally broke the habit of leaving my keys in my pockets all the time. Now I just take them out when I get home.

 

Happened to me once, I was puzzled when I saw the windows and moon roof open.
I had no idea the fob could do this, mystery solved.

 

A fob condom definitely helps to prevent it, without making it more difficult to use when intended. Not to mention making it less slippery and protecting it from getting bashed up if you do drop it.

I wouldn't want to be without it. Just like a good phone case.