query: non-vested spouse did not sign the note

This is normal if the non-vested spouse is not obligated to repay the Note. The only reason a mortgage lender or title insurer will have the non-vested spouse sign the Mortgage is to validate the lien aka permit the lien to take priority over their marital rights, if applicable. In these cases, language should be added to the Mortgage clarifying the purpose of the signature and I usually include a clear statement that the non-vested spouse is NOT a borrower under the Note.