Every time after I race, Xert wants to jack my values sky high. Way higher than I can actually hit. Why is that?
Perhaps it’s this: http://www.runnersworld.com/sweat-science/why-do-you-race-faster-than-you-train
Are your races very different than how you train? If so, then there could be some issues with how the races are interpreted by Xert. If not, then I would tend to lean towards the fact that you have an ability to perform well in race conditions as the article above suggests. Remember that Xert merely looks for patterns in your power to see where your fatigue accumulates (TP), how much fatigue you can absorb (HIE) and what your maximal power is (PP). You can use the fact that you may fatigue differently in races to plan your race strategy an recognize that you may not have the motivation or ability to achieve the same levels in training.
My races are a lot shorter and more intense than my training so I guess that is effecting how the power is being expressed.