This does not happen in my test on the desktop software.
Are you using the desktop or Online product?
What are the values in lines 28, 29, and 30 on Schedule CA?
I am using TurboTax Deluxe 2023 for Mac
Application: 2023.r21.028
Values on Schedule CA, Part II:
Line 28: 0
Line 29: 0
Line 30: 5285
Thanks of investigating this.
Are you married filing separately or RDP filing separately? In this case, If your spouse is itemizing, then you must also itemize, which would cause TurboTax not to use the Standard Deduction.
FTB instructions for Form CA (540):
Line 30 – Amount from Line 29 or Standard Deduction
If your filing status is married/RDP filing separately and your spouse itemizes, enter the amount from line 29 (even if the standard deduction is larger).
If this is not it, come back and we'll look some more.
The filing status is single with total income $5.5k. Started a second return, filing status single, with income $1.5k and also see incorrect value on Schedule CA line 30.
Are you able to be claimed as a dependent? That changes the Standard Deduction. See "Standard deduction for dependents"