I have GeForce 1060 and after setting it ON in Nvidia control panel it still stutter. 
Why it stops when debug is enabled?
Who knows, but I see the same thing when vsync is disabled and the profiler displays. Only engine team can say for sure what’s going on but might be hard for them to reproduce. @Johan_Beck-Noren
I saw something like this on another game engine if the Camera Component has been used.