it's because the persistence issues on Xbox still haven't been patched, but the recent patch released a couple days ago on PC DayZ's experimental branch has patched persistence problems so all they need to do is port the update to Xbox.

might've been a persistence problem, since on Xbox the persistence issue with base items such as tents, barrels, stashes, walls, gates, and lookout towers all despawning randomly, most of the time during a server restart.

Recently I was also having the issue where party chat blocks out proximity chat in game like it used to when DayZ Xbox launched on August 29th 2018, I can hear other people talk but they can't hear me despite having the push to talk button held down.

I still can't even speak in the game if i'm in a party chat with a friend, which I thought was a patched glitch a long time ago but I somehow am having it now.

They said it's already a planned feature once they figure out how to implement it correctly without messing up the entire game, they said their current plan for a proper implementation of M/KB support is creating separate servers for M/KB players so they'll be separate from controller players which I hope to god they do because M/KB players being combined with controller players would ruin the game due to unfair advantage.

At the moment it's likely to despawn, but it's random so it might or it might not. I'd say do not take the time for base building as it takes hours or even days to finish building just for it all to be likely wiped due to the persistence issues.