So, I recently opened up a server to play with some friends. We installed a couple of mods -none is a server utility- and we played for a couple hours. We mined a lot and we stopped playing.
Today, we notice the server only saved a few of the spaces we mined, although our inventory was complete and just as we left it. Then, we mined again and built some stuff. Later the usual server restart happened. When we joined in again, everything was lost again except our inventories. We respawn in the places we left but the changes that were made (mining and constructions) are just gone as if we didn't do anything. The weirdest part is that I -the server admin- keep getting the "Server: Game saved" on the chat, but not a single change was saved. What can I do about it?