Translational Periodicity
 

Has anyone seen anything similar to what is shown in the attached images? Opposite faces of the porous cube that I created are specified with translational periodicity, but something strange seems to be going on with one of the faces in particular.

Does anyone know what would cause it to display like this? I have verified that all faces are identical to their opposite counterparts. Could it be a mesh-related problem? I don't even know if it's an error, it just looks different than usual and I'd rather double check before I start running a solution. I'm hoping it's just a rendering issue and will treat it as such for the time being.

Thanks in advance.

Yes, it is probably just a rendering issue. If you have checked that your mesh is OK then you can ignore it.