Armor Stands despawning when leaving the area for about 3-5 minutes

I had build a showcase room consisting of all my ores and tools and in the middle I had 5 maxed out netherite armor with the silence armor trim luckily after I finished everything I made a duplicate of my world so then I went back to my base to drop all of my extra resources. When I came back, the armor stands and armor were gone. They were not on the ground and I did some testing and I found out that if you leave the area for about 3-5 minutes the stands will despawn along with the armor.