Doesn't seem fair to me. Many home-equity loans, like yours, are tied to the prime rate published in the Wall Street Journal. The Journal number is derived from the base rate on corporate loans posted by at least 75 percent of the 30 largest U.S. banks.
Banks typically recalculate rates on either the first or last day of the month.
Because of the delay among the benchmark banks to react to the first Fed move on September 29, the new prime rate didn't appear in the Journal until October 1. Many banks calibrated its rates at the end of the month, using the prime rate published on September 30. So customers waited until the first of November before their balances were subject to the new rate. But the timing of rate adjustments varies according to your payment cycle, which can begin on any number of business days rather than the first or last of the month. Your finance charges for a payment due in November may have been based on an average daily balance calculated in October-meaning you may have just missed any rate decrease for that billing cycle.