Why does this "1040/1040SR WKS: Cash Charitable is too large" show up when I try to claim the full cash charitable number of $300 on my return?

I am taking the standard deductions for 2020 but I want to claim my cash charitable donations that are now allowed under the Cares Act. However, under the TurboTax entry form, it asks for review and that the number 300 is to high. Why is this? I made more than $300 dollars worth of charitable contributions this year so I want to claim the full $300 if possible.