Since that is a commercial theme, we ask that you please go to their official support channel, so you can get support from the people who know it best: https://www.elegantthemes.com/contact/
Forum volunteers do not have access to commercial products, so they would not know why it is not working correctly. Other community members who may have faced your issue might be able to help you, but your best bet is your product’s developer. We encourage you to use the official support venues, as it allows the developers to be aware of issues with their code and gives back to the community in a more robust way.
I reached out to Elegant Themes and they said that I need a membership to be able to get support. But it sounds like they said it could either be a Divi issue (that they could help with) or an issue with the Child theme installed (from elegantmarketplace.com). Before I pay to get support from Divi, do you know if there is a way if I can try to identify if the issue is with Divi or the child theme?