I played on the Survival Server, which was recently given a reset and I noticed I coudln't fly anymore on the Resources World.
Hello CabanNieves This has been added to the new reset. You are only able to fly at spawn and in the plot world. I believe they added it to make the game more fair for those who don't have a rank. It would be unfair to just be able to fly easily to the end city while others are not able to. Have a nice day.
We also wanted to bring back the major aspect of Survival + with the update to 1.12, you can now fly with Elytras