The server player has full control of their pawn, while clients only seem to be able to use action inputs. We’ve ruled out it being a problem with how we handle movement replication of the pawn itself, a problem with setting up inputs, or a possession issue, which were a lot of our first thoughts when we encountered the issue.
Can you post the code you are using?
Input is always done by the owning client and then if it is not the listen server and you want to do something on the server, you need to call a server function.
Also for movement, I would recommend using the Character Movement Component, as that is setup to handle networking.