Weirdest scripting glitch ive ever seen - CFrame.lookAt and quadBezier bug

im making a effect and im trying to get the part to look at the new point

newArm.CFrame = CFrame.lookAt(newArm.Position, newPoint)

whenever I add that it makes the effect invisible, but when I open a new window it shows the effect (but its rly laggy/buggy) and the bigger the window, the smoother the effect

can anyone help me with this?

video showing the problem incase your as confused as I am →