Lag when testing level

Hi, I start working at a new project because Im trying to learn this engine and I have a big problem. Im learning the engine for about 2 weeks and today something is not right, when im testing the level to see if the blueprint works the framerate drop constantly for 120 fps to 19 fps or even lower, but its not happening instantly, after every second the framerate drops. I don`t know how to explain this better than what I just write. CPU Usage when this is happening is about 60% and the temperature is about 56°C. CPU- i3 6098p, GPU- GTX 950, RAM- 8GB 2133mhz.

Usually performance issues are related to hardware, an i3 processor isn’t very powerful, so maybe you’re doing something in-game that’s too CPU intensive.

Well, i have projects with more blueprints than this one, but there is no performance issue.