California Franchise Tax Board – Code 12 (15 day notice)

2024 Taxes.
Just received a Notice of Tax Return Change refrening 'code 12' at the reason for the penalties due.

I paid in full before October 15th, which was the adjusted deadline for all taxes due in my area, due to the 2025 California Wild Fires. There was a formal notice on both IRS and California sites stating zero taxes due including the filing of taxes, estimated payments, and anything else until October 15th. It was pretty clear.

Also, The Notice date is 15 days before the due date, and this was sent by mail so this only gives me 10 days to challenge. I have not received any other notice from the FTB since paying.

So…

Is this normal to get a notice by mail with a 15 day pay period without any prior notices?

Since I don't have much time, is it better to pay and THEN send a letter to challenge? Call in the next few days? Send letter first without paying and wait for response?

Thanks for any advice.