I searched and didn’t see anything else on this-
Anyhow, several times without warning my car is going down the track in rivals and it suddenly rewinds. Oddly enough this happens when I am about to significantly beat the #1 time by 10-20 seconds or even more sometimes 
Kidding, I am no where near #1 times.
It has happened the most on Silverstone but also Spa and Bernese
Not a big deal (except it interfering with me dominating you all)
Are you accidentally hitting the B button? That’s rewind
No I have the thrustmaster TX with the with not the GTA wheel but the GTE wheel. So the rewind is the bottom left button which I believe is labeled as water. The buttons are non standard and it isn’t Xbox licensed so while all the buttons work they aren’t labeled the same and are located in different places on the wheel.
All of that is to say- no not hitting B and the button to rewind is in a different spot and much harder to hit accidentally- at least for me.
Rewind for me is the Y button.
That’s the rim I want… anyways check the Manettino dial, mine on the 458 rim is kinda sensitive in the up / clockwise direction
trim your right thumbnail. it happened to me too. when hitting x or b shifting, i think it was a downshift, my thumb nail caught the y button just enough. and yes i was about to hit my personal best on lemans in the last chicane which ment two wasted laps in d rivals which take forever. i now know i can shave another 7 seconds off with the accurra but i was a little overheated so its going to have to wait ill later. and yes my nails will be taken down as much as possible without bleeding.
default is b upshift, x downshift, y rewind, and b hand brake. i was so afraid of hitting the hand brake i over adjusted and kicked my own butt even harder. i would have lost a couple of tenths maybe but not the whole lap.