The CARES act allows up to $600 in charitable donation deductions (married), even if not itemizing. Why is our running refund balance not changing after we enter these?

We gave $680 in 2021. I did a test where I decreased the total below the $600 max allowed by the CARES act, to see if the running refund amount would lower, but it didn't. Could this be a bug with TurboTax? Anyone else claiming the standard deduction and having success with up to $600 of charitable donations increasing their refund amount?