Nether Wart not changing sprite when growing, always appears as new sprout

Nextbook 11.6

Netherwart does not seem to mature after much time, however when broken it provides 3+ Netherwart as if fully grown, grow animation/ graphics never happen. In the first screen shot you can see what appears to be baby sprout Netherwart, in the second shot you can see once broken it provides many Netherwart.