Once you request a payout, the Max Loss locks permanently to your account's original starting balance. Withdrawing your entire profit balance would bring your equity back to your starting balance, which equals the locked floor, causing an immediate breach.
Example: $10,000 account grows to $11,500. Never withdraw the full $1,500. Withdraw $1,000 and leave $500 as a buffer. Equity stays at $10,500, safely above the floor.