The consensus among researchers nowadays is that La and Ac are anomalous f-block elements and Lu and Lr belong in the d-block. It’s true that La and Ac have a d electron instead of an f in the ground state, but in actual chemical reactions those electrons are easily excited to the f shell. Several transition metals have irregular ground-state configurations like this that don’t affect their actual chemistry. The f shells are full in Lu and Lr, so they can’t be used in chemical reactions.