Unable to publish Firefox extension

Hello Guys,
I am writing to ask why I am not able to publish my extension. If I try to upload my .zip extension on https://addons.mozilla.org/de/developers/addon/submit/upload-listed, I get a error saying “Duplicate add-on ID found”. I already deleted my previous test extensions with that App ID. Is that a problem?

Thanks and Best Regards

If this is your first release, then simply change the id in your manifest file: