dear dev. team,
there is a small ui problem in the corona render setting>environment tab.
when i clear the mat. button on a corona settings>environment, the material that's related to it in the material editor seems don't synchronized just like usual. in the normal case, 4 corner mark in the slot material should be disapear when there is no any object or feature assigned to it and vice versa.
it doesnt happened to general object in the viewport and in the maxs environment tab, others way it is corona environment tabs problem only.
i've tested with other renderer, vr & mr did it perfectly.
actually i got a little bit confused how to explain this out, pretty difficult for me which words is right to describe this case ..
check the attachments, hope you guys understand what i mean.