Watch Hamilton's onboard through the opening sequence and you can see the car fighting him. Turn 2, the long right-hander — the rear steps out mid-corner and he has to wait to get back on the power. Turn 4, another correction. By Turn 6 he's already managing the lap, not attacking it.
This wasn't driver error. Hamilton ran seven separate qualifying simulations across the session, cycling through setup changes between red flags. The lap times barely moved. The Mercedes was planted everywhere else — he was only 0.08s down in Sector 2, nearly matched Verstappen through the high-speed blind corners — but the car simply wouldn't rotate in the slow stuff.