Why is my render darker after joining geometry? I am working on cleaning up an asset I purchased of a closet (above). I am currently trying to join the closet doors together (frames + glass pane), but when I do so the render gets darker for some reason.
Before Joining:

After Joining:

The difference is subtle, so I would suggest opening both the before and after images in separate tabs and flipping through them quickly. I checked my normals and they are fine.
Any help at all would be extremely appreciated as I am completely stumped.
Here is the blend file:
So I figured out what was happening. Shadow ray visibility was disabled for the glass. When I merged the glass with the frame, shadow ray visibility got enabled again.