Web-ext signing issues

I created an extension for academic research and today I decided I would try to submit it to Mozilla for review. However, my usual process for signing and uploading the extension is producing some strange behaviour.

I call web-ext sign --api-key=user:xxx --api-secret=yyy

The extension times out when signing. Ater a few minutes I get this message:

Error: Signing is still pending, you will receive an email once there is an update on the status of your submission. If you don’t see the email after 24 hours, please check your Spam folder.

Also, a new extension is created on my Mozilla developer page each time I try to sign. The expected behaviour is for a new version to be appended to the existing add-on.

I have tried revoking and renewing my api keys, but that didn’t change anything.

Am I doing something wrong? Any advice is greatly appreciated.