Okay so i went through the entire mod and did all of the steps, then i got to level 20, jumped in the void, got the advancement that i could now fly but whenever i came back into the overworld flight didnt work. i still have all of the abilities like strenght and natural armor, but when i double tap spacebar i cant fly. the weird thing is is that i sometimes fly for 1 or 2 seconds but then i just fall agian. any ideas on how to fix?

nvm found it