Maybe the ‘popcorn’ microwave setting is only for making popcorn in a container, not in those microwave packages.
Which is the only way popcorn should be made in the microwave, IMO. Package popcorn is nasty stuff with diacetyl and the other chemical crap added. Whenever I smell someone nuking packaged popcorn these days it smells terrible to me now.
It’s almost as easy to microwave popcorn in a largish glass pyrex bowl, and way cheaper and better. Pour a single layer of popcorn kernels in the bottom of the glass bowl, mix with a tablespoon or two of oil, just enough to coat all the kernels (I like peanut oil since it handles high temps), and microwave until you only hear a pop every 2 or 3 seconds. Pour into a big popcorn bowl, melt some butter if you like, and shake up the popcorn with any seasonings you like. I like parmesan and garlic salt.