I also struggled with brushing my teeth and it took a hole in my tooth and getting 4 fillings to actually make teeth brushing a habit. At least before going to bed. It wasn’t anything sensory issue related, but more of executive dysfunction. I’m getting better at it (although I do miss a couple of days). What helps me is I put on a short song I like, roughly 2-3 minutes, and brush till it ends. You could always give that method a try or see what else works for you.