GE Profile Gas range not cooking properly

My profile has been converted to LP and my wife, after using it for a year is convinced it does not cook like it should. She grew up with LP ovens all her life and swears it is not cooking properly. (especially around Christmas cookie cooking season)

I don't know where to start looking for adjustments or who to call. GE? People who installed propane and converted it? My issue is that while I don't cook she is on me like white on rice to "fix" her $2000 oven.
Cookies are tanned but raw in the middle, we sometimes smell propane, cakes are not cooked through but she IS A GREAT COOK. For her mother to acknowledge that the oven is not right leads me to believe there is something wrong.

Any asistance would be appreciated.

Thanks,
Dave