There is a bunch of posts on Reddit about this with the Note 9. I've started to see this on mine now in both camera and video mode typically under low light. Using internal memory not an SD card.
I've seen all the reddit chatter too but it hasn't happened to me.
Perhaps to demonstrate the problem.Why is tracking AF turned on while he's taking a picture of food?
Tracking AF is useful if you shift the camera, even if your subject is stationary.How fast is his food moving that he needs to have this turned on?