How to delete PREFIX_NEW(team ID).com.mydom.myapp or TestFlight builds using it?

I have an app live using PREFIX_OLD.com.dom.myapp a long time ago and I want to update it now. But I cannot update it anymore because its AppID that appears in my account (https://developer.apple.com/account/resources/identifiers/list) is PREFIX_NEW(team ID).com.dom.myapp, incorrectly prefixed by the now recommended default prefix (Team ID). Trying to delete PREFIX_NEW(team ID).d.. in order to register PREFIX_OLD.d.. results in : "Remove this App ID? All certificates associated with the App ID will be deleted and any provisioning profiles associated with this App ID will be invalidated." Clicking "Remove" leads to the final rejection: "There is a problem with the request entity The App ID 'PREFIX_NEW...' appears to be in use by the App Store, so it can not be removed at this time."

Yes, the PREFIX_NEW.d.. has been used by my my TestFlight builds that I have uploaded then 'expired' at my best. Questions:

  1. How to forcefully remove the App ID PREFIX_NEW(team ID).com.mydom.myapp ?
  2. Subsidarily, how to erase completely from appstore the TestFlight expired builds so that they do not prevent me from doing 1) ?

I appreciate your help

How to delete PREFIX_NEW(team ID).com.mydom.myapp or TestFlight builds using it?
 
 
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