Add variable class to "SpawmActor AR Model"

I added the node “SpawnActor AR Model” to my level blueprint. When I set a constant class (my AR model) in the drop menu the final application works just fine. But when I try to add a variable class which changes for example after a touch input, the model does not change within the application. The node is connect to the Event tick. I work on V4.26 with ARCore Plugin. Does anyone had a similar problem or know how to fix it?
Any help would be highly appreciated.