Actors flying when the game is played from the main menu

Hello guys!
Me and a friend are making a game at UE4, we are beginners, it’s our first game and we are facing some problems.

Our game is a tank game (AI vs Player) and has an AI Actor that is a Mortar. It doesn’t have life bars like the AI tanks or the player tank, so the way that we found to “kill” the mortar was set his mass to 100kg, disabled gravity and, when the player hits the mortar, it flies away and get deleted. That system works fine if we play the game directly from the game map, but, if we play the game from the main menu, the mortar starts flying around the map. I’ve tried locking his location at X and Y but he goes up to the sky when we play the game from the menu. By now we left the mortar fixed at X, Z and Y, but that is awfull because it’s is invincible.
GIF Showing the mortar flying

I think you are also following Udemy one i also did that same problem is happening with me i am using version 4.16 its happening with you in 4.17 it means i think its a problem with our code or physics i am also unable to figure it out :frowning: