What i recommend for you to do if for a taming one of these bad boys is atleast have one piece of a ghillie suit and fertilized eggs im not entirely sure if this is what activates the mini game for the gigiantraptor if you did all these steps the nest may very be glitched but first try to clear all rocks/plants/trees next to the nest and attempt again.(if doesnt work,eliminate the baby and mom so more can spawn in the area and keep trying different nests)