New world and player limit back to 20 when starting the server

Everything was going well, I had a lot of plugins but it was going well without any problems,

Today i started the server,i installed new plugins,but when the server was starting i noticed that there was a new world,I stopped the loading and then i put the backup and then started the server again

The backup was from yesterday when I finished playing and everything was fine, however when I loaded it today the limit of players went up to 20 and created a new world (with the same plugins that were yesterday without the new ones I installed), I am worried because I have this survival for almost 2 months and we have made good progress

Username is Ign4ac10

And the thing is the backup (automatic backup) is good but when starting the backup the player limit raises again to 20 and a new world is created

Ok.It was EssentialsX the problem,I deleted the plugin and now all is back to normal

Thanks anyway for the help