Do not put FFB filter especially on a T300 (useful for a G27). For a T500 0.65 multiplier coefficient is suitable (avoids clipping). The T300 being I think about 30% less torquey, try the value: 0.43 (the FFB will be good but relatively weak). Then increase the value until the problem starts again then sets 0.05 below. However, the force of the t300rs must be set to the standard value in the thrustmaster profiler (60% for a t500). But remove this filter, no need on a t300, it removes the effect "raw" FFB.
I have something on6 quite like it takes some of the jolts out of the ffb also seems slightly dampened. Feels ok on gt cars too