When player respawns their previous body disappears in hideBody manner after random amount of time. Cause of this is unknown, it seems to be happening at random, happens in 100% cases on full servers (50+ players), rarely (never?) happens on nearly empty server (<10 players), never happens on empty servers (1 player, being host). We failed to understand what event triggers it but it is definitely not a scripted behavior as we don't have hideBody command used anywhere in our mission as well as hideBody never used anywhere in BIS Functions. Body disappears in the same manner as when you leave to the lobby and your active player first dies and then goes underground. No repro mission available, yet bug is easily observable on full server.
Time when bug started to happen is unknown, we first started to notice it 3-4 months ago with introduction of revive feature. It might have been active earlier.