Shift U works fine for me, looking at the pics the ping meter is fairly high maybe that's half the problem of low frame rates.
On a different note, the car reset would be better with a 3rd option Imo.
0 = no, car reset not allowed
1 = reset, car reset allowed with no damage repair
2 = yes, car reset allowed with damage fixed
That's because we run enduros and now if you flip your car it's unfair to have your car fully repaired without making a pitstop, or worse that's the end of your race if resets turned off.
And finally, with W39 I had damage then made a pit stop it said was repaired but after leaving the pits the car still had a lot of damage to the suspension.
I've had this happen a few times in the past too but it's not a regular thing.