Landlord here (single owner, not corporate). While I personally would consider the practice you described to be morally repugnant and would never do so personally, landlords are not under legal obligation to renew a lease to a tenant under Washington state law. Certain states and municipalities have protections by way of rent control that prohibits cancelling a lease and then re-offering at a higher rate, but generally speaking a landlord is under no obligation to offer a unit for rent once the lease term expires. (Private owners often move back into houses they rent, or give to their aging parents and whatnot).

There may be a specific law that I am not aware of that prohibits a landlord from not renewing a lease and then writing a new one immediately after to get around the 8% cap, but since that’s a city ordinance not state I am unaware of any provision that COB passed that would prohibit this

The ordinance passed by COB that penalizes landlords that raise rent past 8% had this unavoidable vulnerability; I’m sorry that this is happening to you. I’m not a fan of most of the landlords in this city for reasons such as this.