Second NiMeRi75's comment. It appears to be an issue with driving the truck not updating the players location - only getting out of the truck will do that.

Does anybody else have information as to whether it happens if you simply log out while in a truck? Didn't think to try that when I had one and don't have the time today to check it.

Can confirm this, 100% reproducible for me. I'm on a private, persistant shard, low ping, happens with 0 desync and relogging does not return the feathers to my inventory.

Are you guys playing on public servers? Bare in mind that each private shard has its own individual characters. Public servers also have different characters for 1st person only servers & normal servers.

Not had this issue personally, despite regularly getting the 'Waiting for host' message and being online when the server I play on resets.

If this is an actual issue, however, it's probably an issue with caching your player to the hive, like you suggested. That's more of an optimization thing (getting it up there absolutely asap). Don't imagine much can be done other than being a bit more patient with relogging.