I use ProSeries, not Lacerte. I looked at the Form 1045, Schedule B instructions, and they do say that SS should be recomputed:

Line 6—Adjustments to
Adjusted Gross Income
If you entered an amount on line 3 or
line 4, you must refigure certain income
and deductions based on AGI. These
include:
• The special allowance for passive
activity losses from rental real estate
activities,
• Taxable social security benefits,

Tell your client that as long as half of Congress wants to prevent IRS from hiring enough qualified people to do the job, you just have to put up with incompetence.