Monthly purchase-bonus progress is based on confirmed credit purchases in the UTC calendar month. Grants and referral rewards are not purchases. Spending credits does not reduce that month's purchase progress, and the existing balance carries over separately.
Check the purchase confirmation time and the month shown in Billing. A payment made near a month boundary can belong to a different UTC month from your local date. If a confirmed eligible purchase is missing, send support its reference and amount. Do not make another purchase merely to refresh the progress display.