Multiplayer client character jitters hitting door actor

I have a client character that spawns on a server and a door actor (door frame and rotating door panel) on the map that the character can open.
If I run into the door (before opening it) the character is stopped as you would expect and all is lovely.
But,
After opening the door (by applying a rotation to the door panel), if I then run the character into the door and keep running forwards the character jitters like mad. This is my theory:-
It appears that the client moves the character forwards and this is stopped by collision with the door.
The Server then gets the change in the character position and decides that the collision should have been a bit sooner.
So the server causes the character to move back a small amount to synchronise positions.
Then the character moves forward that little bit and the cycle repeats.

I have tried turning up the replication accuracy to maximum but it makes no difference. This seems a very simple thing that must be a common issue? I would be grateful if anyone can provide any clues as to what I might do.
The replication is all working fine and all clients can open or close the door and all see it happen.

Also, I managed to get a cube actor to poke right through the door - though they both have collision meshes and both replicate perfectly well. So, what is wrong with my collision handling?
Thankyou.

Hi, did you resolve it somehow?