Don't know how appointment slots they have but if one has a pressing SSA issue might be worth a trip to BKK:
The Social Security Administration's Federal Benefits Unit (SSA/FBU) will provide services on Thursday July 24 at the American Citizen Services Section of the U.S. Embassy Bangkok. We have a limited number of appointments, so sign up now to secure your appointment. Please sign up via the link below. Closer to the date of the event the American Citizen Services section will provide more specific information via email to those who register successfully. https://forms.office.com/g/1Uypg7twD5