Armor stand disappeared

I have a room on the second floor of my house where I keep armor stands with extra armor. I went to get a piece I needed and the armor stand with all my better armor was just gone. What happened???

 

Ignore the “affects version/s” info, I didn’t know what to put there and this website is NOT mobile friendly so it was such a pain to get it to let me fill it in and it wouldn’t let me submit something without filling that out. Honestly that’s like a bug in and of itself.