Taming cats isn't working

Every single time I try to tame a cat on the Minecraft realm I am playing on with my friends it won't work. It kinda works like I feed it raw salmon or raw cod and the hearts appear but after that it won't let me feed it more fish or it won't respond to my commands like when I click it to sit and it doesn't follow me so it won't let me tame it. I'm trying to use cats but I'm getting really frustrated with the game cause it won't let me tame a cat