This must be my week for phantom changes . . . .
Somewhere along the way, MAP began picking up an incorrect value. It's correct on the EIS. I wonder how it's determining 1279?
I noticed that your scale for MP seems to be off. I am assuming a normally aspirate Lycoming (I may be wrong), so the max value you need on the display is say, 35" Hg.
Also, you should be able to set the "system" up so that all values are simply passed through from the EIS and displayed by the EFIS **just as passed along**.
Therefore, I think you have some wrong settings somewhere.
I have multiple displays with the EIS "out of sight". ALL items are properly displayed on the EFIS.