I am using Unity 2020.2.7f1 and my GameObject is moving using rigidbody. The thing is my GO have different speed in Game window and other in scene when I am selecting it in hierarchy or just have locked it in inspector.
Is this Unity bug or am I doing something wrong with physics?
I will not be downloading any RAR attachment with a supposed video in it.
Have you considered a service such as Youtube to host your video?
As with all data-oriented problems, which this sounds like, in order to help you gain more insight into your problem, I recommend liberally sprinkling Debug.Log() statements through your code to display information in realtime.
Doing this should help you answer these types of questions:
is this code even running? which parts are running? how often does it run?
what are the values of the variables involved? Are they initialized?
Knowing this information will help you reason about the behavior you are seeing.
This is almost definitely caused by some code that is framerate dependent. That means it behaves differently when your game is running at different framerates. This is often caused by performing physics actions such as AddForce inside the normal frame Update().
I downgraded Unity to 2019 and the problem is no longer occurs. I don’t think that selecting an object is changing framerates. AddForce is adding in FixedUpdate() multiplied by Time.fixedDeltaTime value.