Carry On Together multiplayer not connecting is usually something outside the game: the Tab player list and the lobby browser both show ping for every player and every room, so you can tell a bad connection from a blocked launch before you start a job.
Carry On Together multiplayer not connecting: check these first
- If Windows blocks the game with a warning that it cannot identify the publisher, allow it to run. That prompt stops the game before it can reach a lobby, so nothing else in the game will work until it is dismissed.
- Check the ping before you commit. The player list shows a ping readout for every player, and the lobby browser shows estimated ping for every room, so a session that will run badly can be spotted from the menu.
- Make sure you are connected through Steam as an online friend. Invites go through Steam, and a session that cannot see your friends cannot be joined from a friend invite.
- Expect a stutter on a weak line rather than a failure. The demo builds made connections with Steam friends faster, players who join late or reconnect now return to the job correctly, and the stutter during the tunnel transition on slow connections was fixed.
- If the audio is the only thing failing, talk it through. T - Push to Talk (Hold) works over a bad connection, which is enough to finish a job when the voice chat drops.
Carry On Together multiplayer desync: what it looks like
A desync is when the two of you are looking at different games. Players describe it as seeing objects in completely different places from each other, and there are reports of objects going through the ground on a job and of objects like a sofa flying on their own.
It is not a loading problem and it is not something you caused by being bad at the game. It is the physics simulation on the two machines disagreeing about the same furniture. If the object in question is one that needs two people anyway, the two-player carry guide covers the lift that keeps both clients agreeing about where it is.
What the demo builds changed
Most of the work in the demo builds went into the physics rather than into a symptom patch. An earlier update removed the invisible collider that stopped players and items in their tracks, made two-player carries smoother so the item no longer drags your partner and the grip does not break, and stopped items clipping into the carrier's body. A later one added smoother players and items and fixed items suddenly launching and jittering during a two-player carry.
The build after that reworked the radar, the job sheet and the map, and made pinging accurate, so the crew has better tools to point at whatever moved.
Working around a desync
When the two views do not agree, the practical move is to stop trusting one of them and start talking. Ping the piece that drifted so both crews are aiming at the same object, and check the job sheet rather than the world to see what is actually done.
Accurate pinging is the tool that was built for exactly this — the ping guide covers the binding and how to use it on a moving piece.