Retirement tax questions

@Opus 17 

 

I was confused when we originally ran the numbers and came up with higher tax liability for MFJ. I generally thought this was incentivised, and couldn't understand why. 

 

When I ran the numbers a second time and saw a modest reduction in tax, I figured that I made some stupid mistake the first time, like double counting the child tax credit or something. 

 

Is there any way to cancel the amendment and revert to the original return?