The three of us joined a game together and yuri disconnected and rejoined. he was not able to rejoin properly so reloaded the tab. After he rejoined the game his lines where not visible for all other players (we discussed this in chat :-D). Every round the invisible player started with 0 points and was also invisible on the scoreboard.
As you can see, his ship was visible (orange at my cursor) but his lines were not.
Edit The replay: https://curvefever.pro/37/replay/SygEWh51xH