Items lost, game does not exist

I was playing diablo 2 and transfered items from one character to an other. I created a game and waited in it for a while. I put the items on the ground and rejoined with the other character and picked it up. Then i got a black screen and it said connection interrupted i think. After that the game was instantly gone and also i couldn’t join or create games with that character, but it was fine with my other characters. When i finally was able to join a game the items i had picked up were gone from my inventory.
It happened about 5 PM swedish time on mars 15. i lost stone of jordan and skin of the viper magi. My account name is Skallepalle.
If you are not able to give the items back can you at least explain what happened so i can avoid it in the future?