I’ve never fully understood how the ‘popcorn’ button on microwaves work (I’ve read different things that may or may not all be true depending on make/model), but my current one always runs for exactly 3 seconds too long and ever so slightly burns the popcorn.
It’s not burned enough to throw it out, but it does give a noticeable “burnt popcorn” smell that kind of ruins my day.
So instead of pressing “popcorn” and doing something else, I have to stand there and watch it to hit ‘cancel’ in time.
TLDW: The moisture sensor might be on the right side of the microwave, and the bag was pointing left when the steam was released.
But that was definitely worth a watch.