The engine may be failing to load config files.
If you have c++ compiler installed, you can edit the settings and recompile plugin;
In OBJPool.cpp file you just have to change it to “true”:
UPoolSettings::UPoolSettings(const FObjectInitializer &OBJ) : Super(OBJ) {
NeverFailDeferredSpawn = false;
KeepOrphanActorsAlive = false;
ReinitializeInstances = true;
InstantiateOnDemand = false;
LoadConfig();
}