epplus Calulations not producing same results

[barryrs]

I'm not sure where to go with this, so I'll drop it here.
I'm trying to verify values written to an excel sheet, but am not getting the same values from epplus as I see in the actual sheet. Could you shed some light on my issue, or give me some advice.
Thank you.

https://stackoverflow.com/questions/59184743/epplus-sum-calculation-returns-a-different-result