Miscalculated estimated tax penalty

Received letter from IRS....,' you miscalculated estimated tax penalty...' including check for THE FULL AMOUNT TTX CALCULATED AS THE PENALTY. Therefore, no penalty was due, but TTX added a penalty.  It further says'... in a disaster area, addition time...may be granted...' I did not apply for any disaster allowance although we are in a recognized 'disaster area'. 

 

Is that why the penalty was refunded?

 

Significant income is reported from RMD accounts. I understand that greatly affects, and may eliminate, estimated tax penalties. How do I know which it is, and how to approach estimated tax payments in 2025?

 

Thanks