Playing in Realms.
Had some armor in a combined chest.
Destroyed one side of the combined chest.
One chest and no armors popped out (able to collect).
Opened the chest that remained on the ground and found it empty.
My armors had disappeared.

Was able to repeat the bug. Had a combined chest, fully loaded the chest. Destroyed the chest. No items popped out. Opened the remaining chest and found items inside. So half of the items had disappeared. However this did not happen every time. Sometimes the bug did not happen (items popped out when I destroyed the chest).