Salem

Got ko'd after going to level 3 mining cave, came upstairs and walked 2 steps and ko'd. Came back immeditatly cause my home stone is outside cave, and inventory is not there?
wiki says: Getting KO from this will however not cause a loss of proficiencies, but it will drop your inventory. where is my inventory? Do caves auto delete drops?

Yeah I ran into something kind of like this as well awhile ago as well when my character was much lower in Popham, tried practicing fighting bats by just stomping them after getting to a new level with 20-30 of them flying around (stomping is obviously not very effective but a good way to learn their behavior/timing).

Ended up getting KO'd a few times before clearing them all but then when I came back after the third KO everything was suddenly all gone. No recent bat corpses, none of the recent inventory, definitely seemed like there was some sort of weird bug going on.

I haven't noticed this in mines aside from that one time though, but then again I don't really ever leave stuff lying around on the ground in mines so I guess I wouldn't notice anyways.

Kinda depends on your inventory items, being inside a cave should not matter IIRC.