I had this issue in all 4 corners of my quad truck. I felt like the motors were "clicking" or "knocking" at very low speeds: that they were engaging from drive to regen or vice versa with a little neutral space in between. Just had the recall "FSAM-1091 - installed washers on all half shafts...
I had this issue after my toddler played around in the car. He set off a weight sensor on the front passenger seat but it didn’t disengage when he left the seat. I fixed the problem by sitting in each seat and put the seatbelt on/off. I didn’t do anything with the child seats in the back.