Amended return - why did refund meter not reset to zero and why do 1040x original amounts not match filed return?

I received a 1041 K-1 after filing my return so I need to file an amended return.  However, when I started the Amended return in TurboTax, the refund counter did not fully reset to zero as expected.  In looking at the Form 1040-X, it looks like the amounts in the "Original Amount" column do not match what had been filed with the original return.  When I manually change these figures on 1040-X to match the filed 1040 amounts, the refund counter does then change to zero.  My questions: 1) why did the "Original Amount" values not match the 1040 filed amounts, and 2) is it sufficient to manually adjust the 1040-X "Orignal Amount" values to match the original 1040 filed amounts to properly calculate the incremental amended return impact, or are there be other areas of the amended return file that would also need to be manually fixed to properly prepare the amended return once the K-1 values are input?  This is disconcerting that TurboTax does not seem to be transferring the original return information correctly.