Hey Rudy,
Thank you for your help, I think refreshing the nodes was part of what fixed it!
At first I tried repackaging the project after refreshing all the nodes in all Blueprints. The problem was not solved. Then I noticed that the parent blueprint did not have a Tick node. I added the Tick node to the parent, refreshed all nodes in all blueprints again and then it worked!
It’s strange that this worked, because the example project does not have a Tick node in the parent blueprint either, so I’m guessing that Refresh All Nodes was an important step.
Thanks again for your support!