Different FPS depending on what object i select in scene

If in Editor while running my scene i select Camera frames are around 45-55, if i select my directional light i get around 90fps. Why happens this? I get this results using Unity 2018.3

 

Unity doesn't update or render as fast as it can in the scene view to help save power and free your CPU/GPU for multi-tasking, as you usually don't need a framerate as smooth for developing as you do for playing. However, when you are doing certain tasks like modifying lights or rotating an object, the scene view will increase the framerate to allow you to see your changes smoothly, then it will revert to the slow frame rate when you are done.

I don't think there is a way to change this behavior, but the frame rate should be smooth whenever you really need it to be.

 

But i am not changing anything, just selecting objects, and its not just directional light, other objects i tried also get around double fps

 

That's about all I know, sorry. I'm not sure if it'll give you much info, but you can open the profiler and set it to profile the editor instead of your game.

 

I have observed a dramatic frame rate dropping when you play a scene and something (whatever) is selected on the hierarchy window.