Piglin with name tag despawning

Hello. While I had some building in the Nether, Piglin was spawn. He was trapped in a room, after some time I named him with a name tag, also I bartering with him after this. When I entered the game the next time I kept working on some building and when I check out the piglin, I realize that it had disappeared.
I think that nothing could kill it, because he was in a locked room. Sometimes hoglins are spawning and I saw one of them was out of the room. But even if it was in the room, I think it impossible that one hoglin was able to kill piglin which has full gold armor (I gave that to him) and an enchanted gold sword.
Is it a bug or are there some other scenarios that made him disappear?

Thank you and I am sorry for my grammar, English is not my primary language.