My former giant corporate landlord (Onni) began refusing to accept checks as a matter of policy, even when I pointed this out exact law, and the language in my

My former giant corporate landlord (Onni) began refusing to accept checks as a matter of policy, even when I pointed this out exact law, and the language in my lease saying the landlord would accept them. They claimed that because the mandatory $5 "convenience fee" on their payment portal was paid to a third party processor, and not to them, that they were in the clear. I didn't want to go so far as to challenge them to either continue accepting check payments or, if they still refused, try and evict me, but maybe I should have.