the suspended loss must be taken in the year of disposition. if it creates negative AGI, you probably have an NOL which would carryforward to next year. The issue you have is that Turbotax does not compute NOL so it will not roll to the following year. use form 1045 schedule A or PUB 536 to compute possible NOL
pub 536
https://www.irs.gov/forms-pubs/about-publication-536
form 1045
https://www.irs.gov/forms-pubs/about-form-1045
