Yesterday (January 21, 2022), I deleted all of my charitable contributions, then re-inputted only one charity. That charity was over $600.
Today (January 22, 2022) the correct deduction ($600) is now showing on my preview tax return. I am using TurboTax Home and Business for 2021, download version, working on Mac desktop. Software up to date as of January 22, 2022.
Either the actions I took yesterday or a TurboTax update solved the problem.
