Vehicles do not synchronize between players

[deepvelocity]

Which version are you playing on?

Latest commit (Only for experts)

Details about version

#2750 pull / a89227d commit

Which OS are you playing on?

Windows

On which platform did you buy Subnautica?

Steam

Describe the issue.

When a player pilots any pilotable vehicle (tested with Seamoth and Cyclops), the vehicle does not move on other players' screens. The piloting player is shown seated inside the vehicle, but both the player and the vehicle remain frozen in place for everyone else. When the pilot exits the vehicle, their own player position then updates correctly for other players.
After reconnecting (or restarting the server), the vehicle's position is reset to where it was originally.
If only one player is present, this issue does not happen.

Describe the steps you took to encounter the bug.

1. Have two players on the server (reproduced with two clients on the same machine connected via 127.0.0.1).
2. Player A pilots a Seamoth or Cyclops and drives around.
3. Observe Player B's screen.

Relevant log output

No response

[deepvelocity]

This is a regression: it did not occur in 1.8.1.0. The most likely origin is the simulation-ownership / packet-handling rework in #2656 (the only post-1.8.1 change touching this subsystem), but the exact faulty point hasn't been confirmed yet.

[Measurity]

Possibly fixed by #2753

[lammmab]

I get this one with the cyclops too. Unsure if 2753 fixes.