Turbotax says:
Sign and date Form 8453-OL within 1 day of acceptance.
The official CA FTB instructions https://www.ftb.ca.gov/forms/2024/2024-8453-ol-instructions.pdf say:
Sign form FTB 8453-OL after you prepare the return, but before you
transmit it.
I reported this problem last year with no response and no fix.
Is Intuit going to address this issue?
Doubt it.