Does the new studio have source control integration?  I can publish an app that is not connected to source control.  However, ones that are connected to source control, fail with the error below.

 

Publish to App Repo failed with error: There was an error publishing app 
Http Status: 400
Status: 3
Status Label: Failed
Status Message:
Status Detail:
Error: There are changes that must be committed or stashed before this application can be published.