I had a similar problem with my 2019 return. Followed all instructions on how to amend my previous return, but the Turbotax auto-entered original amount for Itemized deductions did not match the original amount by several thousand dollars. Good thing I took the time to check the numbers manually against my original return.
To resolve the problem, I also manually created the 1040-X form for submission to the IRS.
I called the phone support on two different days--each time wasting 10 - 15 minutes. The first time, I connected with a rep who couldn't help and forwarded me to a number in which I had to pay $100 for support. The second time, after 10 minutes of useless voice-response interrogation, I was connected to a CPA-qualified rep, or at least I thought I was. The voice asked for my name several times, claiming that they (it?) could not hear me, and then hung up. I like turbotax, but the support from Intuit seems to be non-existent.
