This worked fine for years to calculate value of my I bonds. Since November the calcuated values are wrong, shows that my bonds lost $5,000 in value from October 2021 to November 2021. Bonds were issues in 11/2001. If I enter issue date of 10/2001 or earlier the values are correct. Issue date 11/2001 or later values are not correct, cumulative interest rate is now $5,000 less than last month when it was calculated when it worked correctly.