playing on 1.21.1 on a modpack

at first when i imported over the old files from the 1.20.4 version of the modpack, the entire configuration disappeared and everything was back to default (Menu Item #1 , #2 etc etc) so i just manually added them back in

was working for a while but when i exited the game and came back everything disappeared again

the json file is in its config folder though so idk why it keeps going poof