Threejs Editor material type standard to phong not change

I imported a modeling file, changed the material type of the first mesh from “standard” to “phong,” and then exported it. However, when I imported the exported file again, it had reverted back from “phong” to “standard.” This issue doesn’t seem to occur with other material types like “basic” or “physical.” I’m not sure why this problem specifically happens with “phong.”
thank you so much