rakeback tier dropped

Noticed my rakeback tier quietly slipped lower this week, even though my volume hasn’t changed much - maybe a few less hands, but nothing major. Never really trusted the whole system, since it feels like they’re always tweaking stuff behind the curtain. To be honest, I treat it like those random bonuses they throw at you in roulette when your luck's gone cold - never counting on it, but annoyed when it disappears.

Anybody else have their tier adjusted lately, or am I just imagining things? What do you do to track your actual rake versus what they say you’ve earned?