Server world exporting

Basicly what was happening is that i was running a 1.16.1 server (vanilla) and then I tried to move the world file from the Server folder into my Minecraft saves folder (the one under %appdata%) and then when I open it in singleplayer it like reverted an older save of the world. it did this like everytime I tried to copy the world file and I also like checked a ton of times to see if I had mixed up the files but no. Also when I moved the file in and out of the server folder it just again reverted back to the old file. Oh, and I have been hosting small servers like that before on older versions and I have never had it happen until 1.16.1