Describe the bug
Any plane/vehicle disappears on server.

To Reproduce
Steps to reproduce the behavior:

1. log into a server
2. spawn a plane
3. fly as fast as you can in one direction and eventually the plane disappears and you're unable to place another plane.
   https://streamable.com/4eygd
   (Our server is public and we would be more than happy to demonstrate it for you!)

Expected behavior
Planes don't randomly disappear.

Screenshots
its hard to take a screenshot of something that disappears.

Versions (please complete the following information):

• Forge: 1.12.2-2768
• Flan's Mod: 5.6 - jan 8th bug fix

Additional context
not much more to add. Like i said before we're happy to give you a first hand look on our server to see the issue for yourself. I searched the issue threads already and didn't see anything that matched my issue.

@247Tossing
When you log back in, is the plane still in the world?
Do you log back in at the same location as when you were removed from the plane?

No, the plane is completely gone. It's possible that I just couldnt find the entity because of how fast it is, but im pretty sure if you exit a plane it stop immediately, and yeah it logs it where the plane disappeared.

If by server software you mean like management panels were using AMP, but i dont think that's what you mean. We have SpongeForge installed with a couple plug-ins so I'll see if those are throwing errors, and I'll go test this on my test server to see if it happens on a clean forge server, and in so and report back.

SpongeForge has a config option 'max-speed' that will remove entities going over the configured value.

Please read: https://docs.spongepowered.org/stable/en/server/getting-started/configuration/sponge-conf.html