Firebase unable to edit dynamic link behavior for android app from console

Question

When editing dynamic links in my Android Firebase app I try to define the link behavior for Android by choosing "Open the deep link in your Android app", followed by pressing Next "if your app is not installed, send the user to"

Firebase will not save a change from 'Google Play page for your app" to "Custom URL or Google Play Instant Experience". It "edits" successfully, and then is back to the previous setting when I check it.

Boiler

Response from Firebase: "Looking in closely, it seems that you're using a Dynamic Link as a fallback link in Android. Links used in Dynamic Links must be a well-formatted URL, be properly URL-encoded, use either HTTP or HTTPS, and cannot be another Dynamic Link. I'll raise this to our team to have a warning displayed in the console when an invalid link is used. Let me know if there's anything else I can help you with." – Boiler