Why is Stella Gonet not credited for Traces?

Hi, Chris24. Welcome to the forum of/for the IMDb Community! Either the filmography item was deleted or never added to begin with. If the latter is the case, and an an update never submitted, then the reason could be indeterminate or otherwise speculative. Sometimes even IMDb's finest regular contributors of television series episode information accidentally supply it incompletely. There is also the possibility that the item was submitted yet declined for being somehow hard to verify. If you're more concerned about a solution to a problem than an answer to a question, then please feel free to let us know, or simply submit the appropriate filmography item addition and include evidence in the explanation field of the form.