Posterior open bite from Invisalign and bite issues although teeth “look fine”

I’m half way done with a short round of Invisalign from an orthodontist (I had braces as a child and a full round of Invisalign as a late teen) so I didn’t need many trays, only 8 trays total with bi-weekly changes.

Overall, my teeth are straight and look fine. I have a minor tooth gap which is already resolved around 80%. I do have a moderate overbite and a class II malocclusion (which my ortho said isn’t worth treating (???) I guess it’s minor and is in line with a large majority of people who don’t really get treatment. Anyways, I’m on tray 5 and I have already developed a posterior open bite, and this is exactly what happened on my first round of Invisalign years ago from a different orthodontist.

Basically when I bite down it feels like only the front 4 teeth are getting contact, and my molars don’t touch at all. Visibly there’s a little bit of space, but to most people it would look like my molars touch, but I don’t feel them touch, when I bite down I literally only feel contact on the front 4 teeth and it hits so hard my front teeth are chipping and wearing down.

This is my second orthodontist and third round of treatment and they don’t seem to believe me when I tell them this. I honestly feel like what needs to be done is elastics with either braces or Invisalign to pull the back teeth together vertically so that when I bite all the teeth get equal contact. But I feel weird TELLING my ortho what to do? But like I don’t understand why they don’t understand what I’m experiencing. They seem to not care about bite but looks only?

Should I switch to braces? I know people say POB will settle after treatment when you move to night only wear or cutting the backs off, and that may be true to some extent, but my POB was there even before treatment hence why I have the hard bite in the front teeth and the overbite to begin with. Molars should always take the brunt of the force when biting, they are the strongest teeth and support the jaw. My teeth should not be slamming against each other in the front only. I’m getting very frustrated. I’m going to have no front teeth left by the time I’m older!!