Tridentkiller drops PigZombiSwords

Hallo,

My Tridentkiller at my Goldfarm started to drop Golden Swords. It's a double Portalbased (23x23) Goldfarm with a Tridentkiller (5 Tridents with Mending and Unbreaking3 each). See Pictures. In 1.16.4 I got only Nugets, Ingots and Roten (Swords only If I use my sword too). Now I get Swords without even touching the ZombiPigs only the Tridents hit them. I'm not sure which of the two situations is the True on. For me it's better if I don't get Swords because It fills my storage faster. Divace: Samsung Galaxy A3 2017. PS the farm is superlagy in 1.16.101.