I have my own Minecraft server and I have built a Creeper farm and whenever I'm nearby no Creeper spawn, they only spawn when I fly further away with the Elytra and fly back again. What can I do that they spawn all the time so when I'm around
Yes that is normal
This is to prevent mobs from spinning right next to you and then killing you
No enemy mobs can spur about 20 blocks away from you