Server Not Receiving Input from Client After Successfully Connected To Server

We are using FlexMatch and Gamelift to match players to our Unreal Engine game servers.

Players are matched successfully, put into matches, connect to the server, and their playerSessionIds are successfully accepted in the GameMode of our Unreal servers.

The issue we are having is that when the clients are successfully connected to the game session they can see the map and the moving ais spawned by the server but the clients cannot move or interact with the game server at all.

I even create a simple RPC that, with a key press on the client, calls the server to execute a multicast RPC and log a string to the all clients and server. This is a common event sequence in Unreal and works fine in editor using the “Run Dedicated Server” option.
However when tested with the matched gamelift server the client is unable to call the event on the server.

I’ve been though the client and server logs and there does not seem to be anything obvious causing this issue.

Any ideas on what might be the problem would be appreciated.

Once your clients connect to your server, GameLift is basically out of the way until you need to take a ‘GameLift’ action.

I would check that your server config matches your local dedicated server config etc ie your GameLift hosted server starts and initializes in the similar way to your local server.

Would be interested in “…when tested with the matched gamelift server the client is unable to call the event on the server.” - how are you failing here? Can your client send?

Have you ensured you have all the network ports required by your Unreal server open on your GameLift fleet and are targeting the right server instance?

Thanks for the fast answer @Pip.

After a lot of investigating it turned out to be some settings transferred from the previous level prevented client input. Gamelift had nothing to do with it and didn’t catch it in editor because it only had the current level loaded.
Thanks for the pointers, it helped me track it down.