1- Summon a skeleton
2- Place a repeating command block with the following command;
data modify entity @e[type=minecraft:skeleton,limit=1,sort=nearest] Fire set value -20
3- Set your gamemode to survival
4- See how the skeleton isn't shooting you even though it's charging up its bow and following you around.
It appears that you are trying to modify the data of a zombie, thus the issue is invalid or cannot reproduce.