Amplify clone of existing env fails

I am using the web interface to try to clone an existing env "staging". When I do so, naming it "dev" or "devtwo" in my last attempt, it runs for a while saying:

Cloning env:staging to env: devtwo in app:xxxxxxxxxxxxxx. This operation will take a few minutes.

and then displays this error after a few minutes:

Cloning env:staging to env: devtwo in app:xxxxxxxxxxxx failed

There is nothing else displayed to give me an idea what went wrong and how to resolve.

CloudFormation does not show any error.

Last Deployment Activity shows this for "devtwo":

Time
Resource ID
Deployment status
Reason
3/14/2024, 9:13:10 AM	amplify-xxxxxxxx-devtwo-160951	
 UPDATE_COMPLETE
-
3/14/2024, 9:13:10 AM	authxxxxxxxx (auth)	
 UPDATE_COMPLETE
-
3/14/2024, 9:13:09 AM	amplify-xxxxxxxx-devtwo-160951	
 UPDATE_COMPLETE_CLEANUP_IN_PROGRESS
-
3/14/2024, 9:13:06 AM	analyticsxxxxxxxx (analytics)	
 CREATE_COMPLETE
-
3/14/2024, 9:12:06 AM	authxxxxxxxx (auth)	
 UPDATE_COMPLETE
-
3/14/2024, 9:12:05 AM	authxxxxxxxx (auth)	
 UPDATE_IN_PROGRESS
-
3/14/2024, 9:12:05 AM	analyticsxxxxxxxx (analytics)	
 CREATE_IN_PROGRESS
Resource creation Initiated
3/14/2024, 9:12:05 AM	analyticsxxxxxxxx (analytics)	
 CREATE_IN_PROGRESS
-
3/14/2024, 9:12:00 AM	amplify-xxxxxxxx-devtwo-160951	
 UPDATE_IN_PROGRESS
Amplify backend deployment initiated.
3/14/2024, 9:11:40 AM	amplify-xxxxxxxx-devtwo-160951	
 UPDATE_COMPLETE
-

The "UPDATE IN PROGRESS" and "CREATE IN PROGRESS" never complete (I let an earlier clone run overnight and still showed this in the morning).

Any advice or suggestions?

Our app is using Amplify as a backend for our iOS app. We do not have a web interface.

My goal is to clone an existing "staging" environment so I can try out some new features for that.