Giant Mushroom blocks change side texture

When you place a Giant Mushroom block(red_mushroom_block,brown_mushroom_block,mushroom_stem) against another one, the side it is placed on changes its texture to the brown-dotted mushroom texture.

This may be intentional, but to me it dosen't seem so.

Fix: dont change when placed against eachother, or change back to normal once the second block was removed