Found the problem. As it turns out, the OnWaveSpawned (Brewery5) is some of the C++ in the project. That is why there are multiple of the same type, and it seems they (potentially) all fire off simultaneously. When you right-click and click “Find references” it calls it “Wave Spawned Delegate Delegate Signature”, and when I right-click on it and click “Find actor in level”, it selects it in the viewport. But the blueprint of that actor actually doesn’t contain any said function.
This project is blueprint/c++ hybrid. Probably not the best starting point if you don’t know any C++.