The court ruled that it has jurisdiction over the case, and that some of the allegations are plausible. How are they not investigating Israel for the crime of Genocide?
Is the misunderstanding in the meaning of the term investigate? It very common for justice systems or law enforcement to investigate whether a certain crime falls under a given category, for example Hate Crime.
Now this example is of a local law enforcement, which has pretty liberal laws on what it investigates. The World Court however needs strong conviction to even accept a case. The court did rule that the accusations are plausible and that they have jurisdiction over it. In other words, they are investigating whether Israel’s conduct falls under the crime of genocide.