If you press F12 and make some changes in the camber, tyre pressure, etc, and make a pit stop, on the screen it shows correctly that "setup changes", and it takes 3 seconds. But if you leave the pits after that pit stop, and you make some laps and enter the pits again without making any changes to the setup, you will see "setup changes" on the screen and it takes 3 seconds again!
I have 0.5Q.

Also, if you change the fuel amount to put in while making a pit stop the refuelling process just freezes and your stuck their.

Quote from Vendetta :

Also, if you change the fuel amount to put in while making a pit stop the refuelling process just freezes and your stuck their.

you have to press the enter key after changing the fuel amount so the color changes, then the pitstop ends.