Actually, the same OP issue with liftoff or brake or decel leading to oversteer, albeit mild, and often uncontrollable, even if coasting, or accellerating ever so gently out of the apex, has been plaguing me since day 1.
I got this alot on the medium turns in Autumn Ring Mini, online today, driving the F1 2007. The car handles like a dream on CoteDazur, Nur, Monza, Laguna, but Autumn Mini? Oversteers when decelerating and holding the mid-apex turns, prior the triple righthanders. Mainly the first two turns after the Start/Finish.
I have softer damper in the rear! nope.
I have +.30 rear toe to help it turn! nope.
I have 4/1 brake balance! nope.
maybe the front -.39 toe is acting as if to tug the rear out some more.... hmm
I keep thinking, raise Brake Decel LSD, that'll do it! nope. already at 40 somthing
I raised IT, thinking it will lessen sudden changes in handling. nope.
I softened rear a tad, nope, still sluggish on the medium speed. (Rotary above says it's bad, so I'll raise it and give it a try)
I increased rear downforce! Hey that should plant the rear more! nope, it amplified the problem.
I raised front downforce (lessened it) to allow the front to act less as a pivot point! nope.
Perhaps this track requires some funky settings I don't know about, maybe some radical toes.