Charitable Contribution Carryover issues

I had cash charitable contributions  to qualified charities made in 2021 that I know I can deduct up to 100% of my AGI, minus other deductions. I entered this into Turbo Tax and see it entered on line 11 of Schedule A and in the margin is written 'qualified contribution elected' which would seem to indicate Turbo Tax knew I wanted the 100% limit applied.  I had additional cash carryover amounts from 2016, 2017, 2018, and 2019 but 0 for 2020. However when going through the self guided screens in the Turbo Tax, only the carryovers for 2018 and 2019 showed up. I wanted to use some of my additional carryovers this year. The IRS Publ 526 says when using carryovers use the earlier years first. So I selected an amount from 2016 and 2017 that would use all of the carryover from 2016 and leave some of my carryover intact from 2017. I calculated this amount to have the maximum amount of tax savings while using the least amount of carryover. I entered that amount on line 13 of schedule A. I had to override the amount Turbo Tax wanted me to put into line 13 and summed up my line 11 and line 13 amounts and put that amount into line 14 of Schedule A. I had to override the TurboTax value in line 14 to do this. When I did a Turbo Tax review of taxes these overrides came up as errors. I got a message that the fields I had overridden would not allow me to e-file. I also got a message that using an override can prevent the crosschecking that is important for an accurate return. So I looked at the amounts that TurboTax was providing for line 13 and 14. Line 13 had a number that was the exact sum of my carryovers for 2018 and 2019.  I would have expected the Turbo Tax number on line 14 would have been the sum of line 11 and their number for line 13, but that was not the case. Their line 14 number was the sum of my line 11 number,  Turbo Taxes number for line 13 that was the exact sum of my 2018 and 2019 carryovers,  plus the exact amount of my carryovers for 2016 and 2017 that had not shown up in the self guided screens. That sum was larger than my AGI and was summed together with my other deductions which Turbo Tax entered in my 1040 for deductions.  To report deductions greater than AGI seems incorrect.  Turbo Tax putting in an amount for line 13 that did not use my earliest years seemed inappropriate. The amount Turbo Tax put in for line 13 was more than was necessary, which I would have hoped TurboTax could have computed and their line 14 number did not make sense to me. Disappointed I could not e-file with the numbers I chose. Could you please comment on why you think the Turbo Tax software behaved the way it did? I must also mention that I overrode some numbers in the Charity Contribution Form to agree with the numbers I was supplying. I was hoping that might help with the error messages. I plan to file with the numbers I input unless you see a reason to do otherwise.