And add a line about feedback being collected from all stakeholders before a round starts. Half of my scope creep came from one person who only saw the work in week four.
This was exactly mine. Went sulfate free for scalp reasons, everything was fine for a month, then greasy forever.
Remember hair grows roughly a centimetre a month, so anything you judge at three weeks is being judged on hair that already existed before the change. The only genuinely new hair is at the roots.
Does the damage from the last two weeks stay or does it recover?
Humidity. Above a dew point of roughly 16C, hair pulls water from the air, the cuticle lifts, and everything you did in the shower comes undone. Glycerin heavy products are wonderful in one season and a disaster in the other, which is why the same routine flips on you.