The issue isn't so much how the Kraton is attached to the tang, but how the finger guard is held in place. I have seen a few Tantos for sale on eBay with gaps between the blade and guard like yours, and I can only think that either the knife/guard hit something, or something hit the guard, hard enough to drive the guard backwards. If the guard was only held in place by the Kraton, which is flexible, it should basically return to its original position after an impact, or very close to it. Since that's not the case, it suggests it's some sort of press fit, and it needs to be re-pressed back into place.
It appears that the new Nightfall Series Tantos still use the same Kraton/Kray-Ex handles as the previous models, so they may be able to correct the guard position and then put a new handle on it (or maybe even do it without having to replace the handle). If for some reason they can't help you, I would attempt to push the guard forward back into place and see what happens.