Whenever i respawn and I use vehicle direct spawn, i spend my nanites for the vehicle, i spawn in it and after 2 or 3 sec the loading screen appears and i respawn in the same vehicle but spending nanites on it a second time.
Many times i got the same bug. And not so long ago i noticed, that this bug happens only if i make 3 or more quick clicks on that green spawn point. So it's all simple: more clicks - more doublicated vehicels you get. Now i only make a one double click and everithing is ok. But it's still a bug, and it's not so hard to fix it - devs just must add some delay (5-10 sec) for reading mouse double clicks on spawn point.