I was fighting zombies in a Trial Chamber and died, all of my enchanted Netherite and diamond trimmed armor, was picked up by zombies spawned from an ominous spawner. When I killed all of the zombies none of my armor was dropped and my sword was lost as well. I know that it did not just despawn, because I saw my armor and my trims, which don't appear in the trial chambers, on zombies, and after I had killed the zombies I got no armor back.