If you are creating a right hand curve followed by a right hand curve with a transition between them you will find that the value you set for the transition isn't the same as the one MX creates in the alignment.
MX creates a smaller transition based on internal calculations. The transition length set in the panel is the length from the curve to a straight but as the design is a right hand curve to a right hand curve there is no straight and only a portion of the transition is needed so that is what MX uses. This isn't a problem with the software as it is mathematically correct design value based on the transition formula.
You can set a larger value in the panel to increase the created transition length between the curves.