Boost gauge?

I have 2 tunes that I use. One is a VMP and other is a tune that I have been dialing in(roush). I recently used forscan and changed my factory vac gauge to a vac/boost gauge. When I run the VMP tune I show 9lbs of boost on gauge but when I run the tune I have been dialing in I never go above 0. When I am logging using my tune kpa never goes above 105. I know MP is inferred.
What am I missing here? Why does the VMP tune show correct boost on gauge and the tune I have been working on not? Thanks