Form 8606 and Pro Rata not calculating

I'm amending 2020 tax return to capture missed pro-rata and having issues with TT Form 8606 not grabbing all the info needed through the Step-by-Step option.

 

Back story:

2020 was the first time I had excess contributions in my Roth IRA due to income limitations.  TT created a form 8606 where it placed $5800 in excess taxable contributions as well as Form 5329 where I paid 6% tax on the $5800.  At the same time I had a SIMPLE IRA with a 12/31/2020 balance of $6879.33 but had no knowledge of the Pro Rata rules until this year.

 

Upon discovering this error, yesterday I tried to amend the Form 8606 but found no other option than to force override line 6 -18 to get my 12/31/20 SIMPLE balance in line 6 and hand calculate the rest through the form.  I cannot find a pro rata work around or wizard that places SIMPLE balance into line 6 and/or works through the form other than by hand.  This is a problem because I have a taxable balance of $3132 on line 18 that is not auto populating into line 4b of my 1040 so it can calculate the tax I owe.  Line 4b also does NOT let me override it - at best it wants me to attach a 1099-R sheet for the amount and that would mean I took a distribution from the SIMPLE which I did not.

 

Filing the Form 8606 on it's own without the 1040 is not an option as I owe tax and will need to print out a 1040X with change the in values columns.  Is this an instance where TT does not have the capability to do Pro Rata calculating and I will have to do the 1040X all by hand outside of TT?

 

I have 4 returns that need amending due to my SIMPLE, the back door Roth's I began in 2021 to avoid the above scenario happening again,  and the Pro Rata issues.