Thanks Luke. I don’t think it’s an issue with the gallery width, as the width itself does adjust with screen size. It’s the images that seem to smoosh right up against each other, instead of adjusting their columns from 5 to an appropriate number based on the screen size.
I was able to do it on another site I have, that does not use Jetpack galleries, but rather lists for the images. You can see that here on this page: https://www.trinitylic.org/ If you adjust the page, the buttons for Worship, Ministries, etc fall underneath each other based on the screen size.
The Jetpack gallery does not use lists though, and trying to set the dl.gallery-item to display inline doesn’t work either. I’m wondering if there are some settings on the backend that Jetpack is using that I need to override.