Hello have been playing this with a friend. i found that when i made it to a second planet every time i tab back to my original planet then back to the new one i am back at the landing spot. i have everything from my inventory but i am no where near where i was when started to look at the old planet. i have no other mods installed and i am on the most recent main version (no experimental) version last updated June 23rd.
Edit: turns out the major issue here is when you do not pick a landing site. Then you will end up at the other team's spawn. if you pick a landing site you will end up at that landing site. Does not happen every time but most of the time.
