2018 California Tax Audit

I received a request to check my 2018 California tax return. I had received Paid Family Leave income during 2018, and it looks like my Federal AGI (entire amount) was added as a subtraction for the California AGI as a Paid Family Leave benefit subject to no California taxes. It was my mistake not to check the California tax return in detail, but I saw no errors flagged and submitted as is. Now I am worried what the penalty + interest will be for an amount that was already deducted at payroll and refunded due to an error. Has this happened to anyone else on this community? If so, is there anything I can ask for this like a waiver of some sort - this is my first audit. @audit 

Thanks!