Why has my house disappeared? [duplicate]

I was playing Minecraft 1.14.4 Java Edition, and I'm not the owner of this PRO (my friends and I paid for this server and it included a lot of features and open 24/24) multiplayer server. I was running from the beach that I made it myself into the house (I made the house above water surface) to get some stuffs, suddenly the game stopped and it told me that “Connection Lost”.

After trying to reconnect a few times, finally I can get to the game. As usual, people will spawn in the place that they stood last time, everything disappeared and I dived into the water below my house. At first I thought it was not 100% loading so I restarted the game and it still showed me that a part of my house disappearing. The strange thing that the house was missing in the perfect way (rectangle). And there is no one in the server except me because that time was around 3:15am.

I am really messed up now and I have no idea of what is going on... Can someone help me to figure out why my house disappeared?

Bellow are some images of where my house is missing.

Update: I came to check all the houses of my friends and some of them have this problem. But I have the biggest house damage. Our houses are very FAR (so far) away from each other and it takes us about 5-8 min to walk to each other’s houses.

Correct me if I'm wrong, but I expect your server hosting to not be the best on the market, since it's a small server for you and your friends.

I have my own experience from situations like these. Since the missing part of the house is a perfect rectangle, I think the cause is a chunk resetting to it's default state.

This is almost 100% caused on the server side, eg. your server hosting. The files containing these chinks may have got corrupted, thus resetting themselves to their default state.

Your server hosting site should create backups of your world regularly. If you know how, replace the removed chunks from a backup, if not, load the whole world from your backup. Keep in mind that backing up your world will remove some of your recent progress.

If you'll need help with any server-side stuff, contact your server hosting, they should be able to help.