level starting problem

I have made several mino projects where is for example in my rollergame 10levels and I have made level select widget which opens in when starting game: Here is Blueprint (every project used almost same basic blueprint): nimetön.jpg
Problem is that sometimes about 15-20% in cases unreal editor didn’t answer and loading map takes 15-20second even I have made loading delay 5-seconds. My computer is Asus ROG series and this project is so small. Is there other way or blueprint to use? It is shame because project almost ready to publish, but if loading last almost 20second it is bad think for player/buyer

Have you tried streaming the levels in?