I have T300RS but:
Overall strength in Thrustmaster Control panel (outside the sim): 75%, and then on the two values under it i have 100% on both. The last ones "spring" and "damper" i have 0% on both.
In rF2 per car i have FFB Mult betwen 0,60-0,90 depending on car. Smoothness to 0% or 1% if the car needs it (harsh feeling in FFB). Min Torque i have 2-8% depending on car. Roll out from pits at low speed and raise this number until the Wheel start oscillating (swinging from side to side fast) and then roll back value 1 step at the time to stop it.
Furthermore if you have no feeling in corners maybe you just drive to fast and lose grip? Losing grip is felt as losing FFB, but maybe there is some other issue. Hard to know.