Thank you for your help. As mentioned several times, however, my problem is that the CARES act screen never showed up again after the first time I did the final review. I've entered my cash donations to the usual screen that adds up to >$300 (per the Review All Your Charities page), but that never changed the final number. I'm convinced at this point that this is a glitch in TurboTax's system. You could try to replicate this by doing a test filing, go through the donation page, enter $300 into the CARES act page, then run a final review (which will ask you to verify that cash donation number to put in box 12b). You'll likely find that you can't access the CARES act page again after your final review, and whatever you do to change the Charitable Donation page will not matter unless the value is so high that it shifts from standard deduction to itemized.
I'm probably going to just give up at this point, but wanted to let you know that there's a bug in your system.
