The 'SO509000' screen is already used in the current customization project. Select another screen.

Wondering if anyone can offer some insight here. 

I was working on adding screen SO509000 to the mobile app and I was having an issue with the site map schema which I have since figured out. 

When I went back in to create a new customization of the mobile app by adding SO509000 screen I am getting the following error: 

‘The 'SO509000' screen is already used in the current customization project. Select another screen.’

The issue is that I have unpublished and deleted the original customization project that had this screen in it. 

Since then I have attempted the following. 

I have unpublish all of our customizations and republished the ones that are relevant and verified that the screen SO509000 is not being used in any other customizations. 

Additionally, I can still see the initial object that was created on the mobile app even without a customization or a Mobile Workspace telling this to be here. I have tried to reset the Mobile Workspaces to the defaults as well. 

It would appear that the something of the original customization is an artifact somewhere in the system, but I am not sure where to look for it to remove it and rebuild the customization.