[1.14+] Pigmen zombies attacking everyone in servers

29/06/19: Me and 1 of my friends go to the nether for building railway for reaching strongold.

My friend accidentally hitted a pigman and then he dies.

After this, he come back to the nether, but the pigmans was following me.

Fortunelly, i don't die because they was far and i mine some netherrack with my pickaxe.

Then, for saving us, i execute the command: "/kill @e[type=minecraft:zombie_pigman]" and all die.

When we return to the nether, they was follow we. I rexecuted the command again and they die.

Please fix it, won't use cheat again.