Alright - I had to set up an excel spreadsheet but I found what was causing the difference (thank you for
@macuser_22 for pointing me in the right direction!):
When I "Preview My 1040" in the My Account>Tools>View Tax Summary, the "ROLLOVER" properly shows up on line 16b as suggested by
@macuser_22. I have a schedule E (rental income), which shows a value of -10k on line 17.
When I then remove the 1099-R completely from TT, the "ROLLOVER" and value on line 16b disappear, as expected. However, Schedule E shows a value of -18k.
So adding the rollover together with the change in Schedule E accounts for the difference in total income as well as adjusted gross income.
Nonetheless, it is still unclear to me how Schedule E would change based on the addition of a Rollover...
