Retirement tax questions

I've got a 1099 R for 2025 which shows the gross distribution (contribution + earnings) in box 1 and the earnings only on in box 2a.  I can amend 2024, but the 1099R is for tax year 2025 which would also be reported in tax year 2025 so it seems like a duplication.  The majority of the earnings would be for 2024, but there would be 4 months of 2025 earnings too.  I don't have separate 1099R's for 2024 and 2025 breaking out the earnings by year.   I was told we'd have a 6% penalty on the contribution error but I'm not sure if it should be in 2024 amended or 2025 tax year.  What are your thoughts?  Thank you.