Possibly not entirely fixed. I tried going in with my friends and the cart got stuck again.
Not fixed. A combination of the engine upgrade and the changes made to netcode and predictions in the Summer Cleanup update appears to have caused a regression.
Though possibly related:-
When approaching the boarding station, sometimes âghost cartsâ (heh) can be seen at the station. These canât seem be interacted with and are visible very briefly for a moment or two before disappearing completely. They tend to make an appearance several seconds before a cart is actually due to arrive. Itâs difficult to document this as it is hard to reproduce and it happens so quickly.
This seems to suggest that maybe the carts are not being replicated to where the server says they should be, and may be the root cause for the carts getting stuck in the tunnel.