I discovered that the Web Editor template (Instant Apps) doesn't allow for normal pop-ups. Apparently, users can access a pop-up via multiple clicks and interacting with the Selection pane, as described in the solution in this post, but I feel like that's an unreasonable way to access a pop-up. I think the whole point of pop-ups is to show information in a quick, easy, intuitive way, and the current pop-up situation is none of those things.
Can you please change the Web Editor template to allow pop-ups when simply clicking on a feature on the map?
For context, my use case is an app where users share adventures they've been on. They can edit in order to create a new feature about their adventure. A large purpose of the app is to browse other people's adventures, too, so this is why pop-ups are essential.