Something I keep running into with people who run billable teams, whether that's an agency, a dev shop, or a consultancy.
Scope drifts on a fixed-price project in week three. The client asks for one more thing, the team says yes because the relationship matters, nobody reprices anything. Here is how long it takes to show up:
Week 4, timesheets for week 3 land, some late. Week 5, managers approve them. Week 6, the month closes. Week 7, the management pack comes out and the margin is finally visible.
Four weeks of burn at the wrong rate, discovered a month after it started. By then the money is gone and the only lever left is to eat it.