I can't place seed on certain farm land in the latest snapshot

Ok so I made a hardcore world in the latest snapshot and so I began on my underground farm and when I tried to place my crops only some placed and then I replaced the dirt block and still didn't work. And then when I made a new row of seeds when I placed the last seed it broke like six seed it's been really frustrating hopefully it gets fixed in the next snapshot

 

Thank you

 

Wasabiwastaken