Federal Amended Return (1040-X) Error

I had to amend a return because the 1099Q was an "unqualified distribution".  It was an issue related to a Social Security # that was not updated for the siblings that replaced the original recipient.   It was my understand that the “original recipient" is required to report this unqualified distribution on an amended return.  The return was completed and mailed to the IRS and to the appropriate state.  However, I just realized that TurboTax did not reflect the second Stimulus check ($600) in Column A (original amount).    Should we wait for the IRS to send a bill for the additional $600 or forward the additional funds?  I am confused that Turbo Tax did not reflect the original credit for $600 which was reported on the original return.