Does this YTM calculator work any better?
https://iqcalculators.com/calculator/yield-to-maturity-calculator/" class="bbc_link" target="_blank">https://iqcalculators.com/calculator/yield-to-maturity-calculator/
https://iqcalculators.com/calculator/yield-to-maturity-calculator/" class="bbc_link" target="_blank">https://iqcalculators.com/calculator/yield-to-maturity-calculator/