Problem with a specific game

Hello everyone, i’m a multiple game game developer. In one game in particular i have been getting randomly a big amount of lag and FPS de-crease. I have been trying to set a faster connection, changing over and over the roblox studio settings, i have tried to reset studio, my windows version and more, but nothing. Can someone help me with the issue? it’s almost been a month since this happened, and i don’t want to leave my biggest game so far.

Thanks