I ran this mission two weeks ago and no, it's not broken. I got first and even improved on my previous PB.
Everyone struggling here should have a look at the wind conditions as they're definitely a thing in this
challenge ( as in many other missions ).
You will possibly have to exit and re enter a few times to get optimal settings.
Regarding the video above I'd say, try to overtake the second AI car on the inside. It's possible without contact.
And ignore that bs driving line.