Where would you start?

I have a 6 year old non verbal boy with ASD that recently begun services again after a 3 month break from private speech. (My guess is due to school, he received ST/OT in school but hasn’t had private speech since 3) I’m curious where you would start with a patient like this. He does not enjoy toys, gym equipment, music. The things he enjoys are water play and his mom’s phone (so he can watch Netflix). Often times, he comes in happy and smiling, splashes in water for a few minutes, and then cries until he gets the phone or his bottle (yes, still drinks from a bottle). I haven’t introduced AAC in a few sessions because he had a meltdown when I brought it out so I took a step back to continue rapport building. He will also lay down and “fall asleep” as an avoidance behavior. Mom says he’s always been like this and he sleeps at school. I feel bad because I feel like he’s been on the back burner for so long since he’s not aggressive (I understand teachers are overwhelmed, if a kid can be calm with water/Netflix why disturb him?) any other tactile things I can try? He does mouth objects so I can’t explore much with playdough/sensory bins. Idk how to show him “we’re just here to play” when he doesn’t want to play!