Button Doesn't Work Preventing Spider From Spawning

WHY

 

Spider shouldn't spawn if there are a button at the middle of solid blocks. It is because spider need 2 solid blocks without button to spawn. 

 

IMPACT

1. Button no longer useful to remove spider from spawn
2. Ruining all creeper farm design

 

CONCLUSION

If this still happen in future update, then it's no other way to prevent spider from spawn.