Can I forcefully remove tenant app?

Sunset

I have been asked to update a BC13 database to cloud.
Going therough the motions, it stops already at trying to uninstall-navapp as there seems to be some remnant of an old app registered as a tenant app. At least it says Scope: Tenant.

The customer runs an OnPrem solution as a singletenant, so there are no tenants where this is installed. But I am having a very hard time uninstalling the app in question.

If I try to uninstall on the default tenant, I get an error saying that it isn't published.
If I try to unpublish it, it says that it is in use by the default tenant.
If I try to Sync-NAVApp I just get a message saying that it is already synchronized.
Sync-NAVTenant doesn't seem to do anything. with and without clean mode

Does anybody know of a method where I can force the application out? The customer doesn't know what the app is, and does not want it. So one solution would perhaps be to just remove it from the NAV App table, and see what happens
But before I try that; does anybody have any experiance with a similar situation, and were you able to fix it?

juga

Had the same or a similar problem in bc13 with an app.
What i found back then was that for the app there was an entry missing in the table "App Publish Reference". After adding the Entry via SQL Management Studio to this Table i was able to uninstall the app via powershell.