In past years, if you had a form 8283 with a signature requirement, turbotax would e-file the return but then tell you to print a cover page and mail it to the IRS with the signed original 8283. I was also told this was not happening in 2024.
But, assuming this has been changed or broken, it's an easy fix. Go to the IRS and download and print form 8453. Fill out the top, and check the box for form 8283. Mail form 8453 and the signed original form 8283 to the address in the instructions. Keep copies and use a mailing service with proof of delivery.
https://www.irs.gov/forms-pubs/about-form-8453