Where is your source of truth? The member is correct
The Social Security trust funds are invested entirely in U.S. Treasury securities. Like the Treasury bills, notes, and bonds purchased by private investors around the world, the Treasury securities that the trust funds hold are backed by the full faith and credit of the U.S. government
https://www.cbpp.org/research/social-security/understanding-the-social-security-trust-funds-0#:~:text=The Social Security trust funds are invested entirely in U.S.,credit of the U.S. government.