From a purely technical grammatical point of view "always still doing his homework" seems logical, but this is just not said in English. You can't use the combination "always still" or "still always" in English. However, the words "still" and "always" might happen to be juxtaposed in English, but not in the sense you're proposing, for example: I told her I would be there for her, always, still, she would not trust me.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.