To the OP,
I also bought a Wahoo Kickr Core this week. While setting it up, and registering it on the wahoo app, I got on email with a heavily discounted offer for zwift, if I buy it through wahoo. I then got a code that I entered into zwift.
It's for a 1-year subscription, though. Worked out to about $10 a month.
Maybe check if you didn't get a similar offer
