So I have a weird issue that I don't really know how to describe. I run a multiplayer server for me and friends to play on using port forwarding. The server has been up fine and we haven't had any issues until now. Last night when I went to open the server and log in, I noticed that the world didn't save properly. Like previously I had put this big stone roof and attic on our house and all that including all the diamonds we found had disappeared like it corrupted or something. I thought no biggie, we will just grind for it again. But today, I logged in, and everything was back to normal. The roof and everything was there like we never even logged in last night.
Every time we have all logged out for the night, i used the stop command to close the server and save it. Last night I even tried the /save-all command to make sure it wouldn't revert us even farther but that clearly didn't save the world. What is going on? I haven't been able to find anyone else having this issue and me and my friends are worried about playing because who knows if the world will actually save or not and all of our work would be for nothing. I am thinking now of backing up the world just so that everything will for sure save but since it has done this back and forth thing, I am not sure which save of the world it will actually back up.
Thanks for any help in advanced, I really appreciate it.