Environmental reflections cover diffuse colors

Using cubemap as an environment reflection map, if the reflection intensity is higher than 0.4, the exposure effect will be produced, but if it is less than 0.4, the reflection effect is difficult to see.

Thank you for your attention. I have changed the material type from phong to physical. It seems normal. I suspect it is specaluar map.

I want to inquire about the web-based project released by DaChan playcanvas, what are the restrictions on the browser platform? I never found the relevant document

Thank you very much.