"Already_Pro" when trying to sign up for another year with 50% off

I have 2 weeks left of my pro subscription and I wanted to take advantage of the 50% off promo happening now. When I try to pay, it says “Already_Pro” and doesn’t let me.

If I wait until my pro expires in 2 weeks, the promo will be over. It seems like not only a bug but also unfair.