This bug was found upon answering a question for another issue.
Upon testing, if a player dies, and decides to either:
(MP) Leave the game session before respawning, and then rejoin at any point afterward.
or
(SP) Save or Autosave the session before respawning and then loading from that save.
Will result in the player respawning upon rejoining the session, the players body will still be where it was, without a death crate or death locator, and the body can be revived or downed again, but the inventory in inaccessible.