I have an issue where I use Unload Stream level but the node will not move on and execute anything after it and in the blueprint browser it just sits on streaming level please wait. The level does Unload, but I cannot put anything else behind this Node or it will not execute.
I was wondering if this is a bug, or if its something I did wrong on my end. I can give screen shots but there really is nothing special about the setup its just moving from one level to the next.
Same issue here, slightly different. I have 2 differents IA levels, one normal and the other for demo purposes. The demo one unloads and everything goes on fine, but unloading the normal one hangs the BP execution flow as you said 
I just had this problem. It turns out that if your make your level always loaded, unload stream level node wont fire completed. So I made all my stream levels blueprint loadable and loaded first level on beginplay. Then when I unload that first level it fires completed and continues executing next nodes.
Idk if this is intended or not. If it is a note in the explenation of that node would be great.