Solved

Pit stops

What did you try to do?
Checked every single past race.

What happened instead?
Nothing

Did the problem happen while using wi-fi, mobile data, or both?
Both

Did the bug happen in the app, on PC, or both?
PC

What operating system is your PC?
Win 10

Which browser did you experience the problem in?
All of them

Can the bug be reproduced?
YES, just check all the race results.

Additional comments:
How come that every pit stop is excactly 3 seconds, even when both cars pit at the same time.

You must have no refuelling active so there is nothing to differentiate pit stop times.

Really, All teams do excactly 3 seconds tyres change. What about cross threaded nut, or someone drops something. You could have several reasons, Nobody is perfect. 

You are introducing things that don’t currently exist in the game to try and justify your viewpoint.  The only criteria that currently affects pit stop times in this game is fuel load.  In no refuelling this can’t apply hence why the pit stop times are the same.

Jose has already confirmed this by selecting my first response as best solution.