Inconsistent Realtime Shadows

We're experiencing this odd visual inconsistency between builds of our game run on our local machines and builds of our game run on lower end graphics cards. Normally this is not an issue. Though our game runs slower at higher quality levels on lower end machines, the visuals themselves have, for the most part, been what we expected.

Someone looking over the game for us, however, found this very odd situation which you can see in the two attached images. First, take a look at a similar camera angle from within editor. The shadows scene in this picture are real time.



Now, take a look at the picture that was sent to us by the person testing our game.



As you can hopefully see from these two images, the shadows around the chess table are different between the two renders. I believe this was happening in another part of our game, but it's drifted over to this specific situation in recent days. For some reason the chest board and the white chest pieces are not casting realtime shadows. If the chess board was casting a shadow correctly, we'd of course see it's shadow on the wall. If the white chess pieces were casting their shadows correctly, we'd see a second row of shadows below the first row of shadows, which are being cast by the black pieces.

Thus, I would like to ask this. Has anyone else experienced this where some objects in a scene decide not to cast shadows? Is this some optimization of Unity's or perhaps a limitation of the rendering? I will also note, there is no baked shadow data in the unity scene in question.

 

Not sure if I can help here or not, but I seem to remember another post similar to this with a similar issue.
The problem with the other scene (memory) was the models had some odd pivots. They were not centered on the mesh, which caused the shadows to cast incorrectly.
May want to check that.

 

Does the chess table use a nonstandard shader? On low end hardware it might be falling back to a shader that doesn't cast shadows.

 

Thanks for the suggestion, Goonter. The same shader is being used on the chessboard as well as the neighboring chair, and now that I look a bit more closely at the picture above, I can see that the wooden parts of the chair are also failing to cast their shadows correctly. That seems to be address the issue in this particular situation, at the very least, and gives us something to look out for in other areas.