2023 Master Reverse issue

[Justsail]

I recently bought a l2h2 master van to tow my 1600 kg trailer.
All good going forward , but will not reverse even a slight incline without jerking and banging.
Been back to dealership , came back as normal because it's a AMT transmission.
As these are trade vans one would expect it to be able to tow a trailer.
After many discussions, the dealership bought it back , a big loss to us.
Has anyone had the same problem with their master van ?
Thanks