RSEARCH INDICATES THAT WHEN LACKING A SSN OR ITIN FOR AN NON RESIDENT ALIEN WHO IS FILING SEPARATELY ENTER "NRA" SINCE THERE IS NO INCOME

If the non-resident alien has no SSN, why are you asking if their Social Security is taxable?   They cannot get SS benefits in the U.S. without a SSN.    OR do you mean they get benefits from a different country?

MY SPOUSE LIVES ABROAD AND/OR DOES NOT HAVE A SSN

https://ttlc.intuit.com/turbotax-support/en-us/help-article/taxation/married-person-claim-head-household-filing-status/L078u1RSW_US_en_US?uid=lmtc1ov4

https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-credits-deductions/file-taxes-spouse-nonresident-alien/L4AuRKrMd_US_en_US?uid=m5r1a77j

https://www.irs.gov/individuals/international-taxpayers/nonresident-spouse