Piston texture doubled up (1.8x)

The sticky piston, while lying on its side (only while facing positively on the Z axis) has a broken texture on the top. Not using a texture pack of any sort, not even the beta textures. 

May be related - This screenshot was taken while running latest version of the official bedrock server software. 
This still does occur in the regular game, however, with the server software offline.