Landlord says my hair keeps clogging the sink but I only use it to wash my hands and brush my teeth.

Hi. I live in an apartment where my pipes are connected to my neighbors. When my sink gets clogged, hers gets clogged too. Both my landlord and neighbor keep saying that it’s my hair that causes this problem. One time the plumber came and took out a bunch of hair but ever since that happened I don’t throw any hair in there. It just continues happening over and over but how is it possible? As I said, I no longer throw hair in there. I don’t even cut my nails in the sink anymore or wash my face. Just my hands.

I have to keep buying Drano no unclog it and my landlord just says I should use Drano every 2 weeks and it’s too expensive. What should I do? How is my hair getting there? I understand if it happens in the shower but not where I brush my teeth.