App Store Connect App Clip section crashes when adding default experience (UI bug?)

I’m trying to configure an App Clip in App Store Connect, but the UI crashes when interacting with the App Clip section.

Problem

When I click on the Subtitle field under the App Clip section in the App Store version page, the page immediately shows:

“We can't process your request.”

The browser console logs the following error:

TypeError: Cannot read properties of undefined (reading 'appClipDefaultExperience.id')

This suggests that appClipDefaultExperience is not initialized on the backend/UI state.