Role of band gap in Amset input

Hi Alex

I performed electrical transport calculations for 2 systems using GGA-PBE. However, referee suggested me to use at least meta-GGA (mBJ) band gap. He further added that to avoid expensive calculations, just take PBE results and feed the band gap (by mBJ) manually in the Amset input. I did the same, however, results were exactly same. The band gap values are 0.30 (0.90 by mBJ) eV. I wonder the role of band gap in the Amset input. I am curious to know the reason behind the exact same results.

Looking forward to hearing from you.

Regards
Zeeshan