I had the same problem as yours and the solutions below were not working because for some reason TurboTax had also 'doubled' my carryover from 2018!! Very very disconcerting. Anyway, after I also then fixed the amount in the "1065 Depr Opt" section 4a and 4b did the error finally go away.
If this is the state of the software, I am really concerned whether my taxes have been accurate over the years!!
Hope this helps someone.
