@marcustonndorf I had the same problem and asked at xentral - it is probably currently like this - if you landed on the following page again, and it looks like here, the installation went correctly.

Ah...Ok. But if I click on the app in Shopify there are no settings, nothing, it just brings me back to the screen you also posted. 

Until now we’ve use it with the Shopify API Advance.

What should we do in Xentral to swap to the new one.

If I go to add Shop Interface in Xentral, it just says; “install this in Shopify” which I thought then we had done...

Hello Markus, 
 
I understand that the current process can still be a bit confusing. 
 
Here is a complete guide for the process:
 
To ensure that you are using the latest version of the Business Operations App, please update your app. Please follow these steps:
 

1. Log in to your Shopify shop and navigate to the admin area.
2. Go to the Business Operations App by clicking on Settings → Apps and sales channels → xentral Business Operations.

Afterward, if you have not yet executed the update, you will see the following view:

Please click on "Update App" and follow the instructions.
 
To ensure that the connection to Xentral, status updates, and inventory synchronization work, you need to use at least Xentral version 23.0.39 and the latest version of the Xentral Business Operations App.
 
After installation or update, you will continue to receive the following message:


This is currently normal behavior.
 
The reason for this is that in the app, you could activate product synchronization bidirectionally. To prevent the app from executing unwanted automatic actions, this option was "hidden."
 
With one of the next versions, this will be displayed "normally" again.
 
If you do not see the "Update App" button and are having problems with the Shopify interface, I recommend reinstalling the app.