Capital Loss carryover from 2020 Schedule D used for AMT

TurboTax Support,

 

I am doing the capital loss carryover numbers from 2020 and the there is a screen for "information of 2020 schedule D use for AMT"  coming up with "Adjusted shortterm gain or loss ( Schedule D for AMT, line 7 )" with a number I can't find anywhere in my year 2020 tax return. I went through my filing papers from last year and I can't find the "Schedule D for AMT" form and don't know where that number came from. After continued to next, it seems TurboTax doubled my 2021 capital gain and took ( minus ) it from my previous yeas carryover, so it lower my carryover loss a lot for next year. Wondering where this Schedule D for AMT, line #7 comes from and what it is. Why Turbotax doubled my 2021 capital gain then minus it from my previous year's carryover amount ?

 

For example:

Carryover from 2020 :    -20,000

Total Gain/Loss before carryover :    +150

Capital loss used in 2021:                  +300

Loss carryover for 2022 :                    -20,000 -(+300) = -17,000  which should be -20,000 - (+150 ) = -18,500.

 

Where does that "Capital loss used in 2021: +300" number come from, and use the actual loss number : +150 ?

 

Please advise. Thank you for your help.

 

John