Confused as to what modifier is pulling out timing on a C7 Z06

19 Z06, all the boltons with a 18% OD. Finally got the car working well. Then I noticed in 5th it was down on timing. MAT didn't go over 149 but it pulled out more timing than it should have based on IAT timing table. I'm confused where the total amount is being calculated.

Thanks!

Seen your email!! It?s Manifold air temp (mat)

It?s iat table and uses multiplier table.. log iat advance and will show and correlate with MAT