Audio numeric values don't hold when using the AAC Codec

Hello,

I was using ME to format a bunch of videos that have very specific specs:

Video - Bitrate range, Codec High Profile levels, loudness normalizer settings, and all are good. The one thing that doesnt hold is the AAC codec which is requsted. When I choose it and select 192 kbps, that value changes when I check the final MP4. Its aroundf 188, which fails the publishers needs. 

If I choose MPEG instead of AAC, I can hold the value at 192 when testing.

Can someonbe help me figure out why I cant get the AAC codec to stay at 192 after the file compresses?

Thanks in advance for anyone that may be able to help here.

Cheers,
Babs