I am getting this weird braking/HFI behavior on FW 5.02. I was previously on FW 4.00. I’m running HFI on a FSESC 4.20+ Dual with TB6355. Whenever braking, as soon as the tracking switches from sensorless to HFI there is a grinding sound and vibration throughout the board. The brakes are strong while decelerating until I get below the sensor less ERPM threshold and into HFI tracking then they suddenly become weak. The grinding only happens while HFI is on. The grinding increases intensity until the speed reaches around 1mph and then there is a jolt where the it goes away and braking gets super strong again.
Here is a video of me going down hill and slowing down at the same time.
You can hear clearly near the end of the video where the grinding goes away and suddenly breaking power returns.