I do not believe that the block is being rendered as transparent, they most likely did fix this as it works fine with other blocks. Because you can still see through them though, it is most likely due to the added layer grass gets for color in biomes. That is probably "transparent" so that it only applies the color change. My hypothesis would mean that the issue lies outside the normal area that one would expect to look in code to fix such an issue.
Tyler Scarbrough
I do not believe that the block is being rendered as transparent, they most likely did fix this as it works fine with other blocks. Because you can still see through them though, it is most likely due to the added layer grass gets for color in biomes. That is probably "transparent" so that it only applies the color change. My hypothesis would mean that the issue lies outside the normal area that one would expect to look in code to fix such an issue.