Can't get Elder Guardian spawn egg when middle clicking (pick block)

You're unable to get an Elder Guardian spawn egg when middle clicking (pick block) an Elder Guardian. However, The spawn egg for the Elder Guardian exists in creative inventory.

Steps to Reproduce (Only affects Minecraft Windows 10 Edition)

• Make sure you are in creative mode with cheats enabled.

• Via command type /summon elder_guardian

• Middle click (pick block) the summed elder guardian.

• You were suppose to get an elder guardian spawn egg, but instead nothing happened.