I tried to place a cartography table.
What I expected to happen was...:
The Cartography Table would be placed
What actually happened was...:
A Fletching Table was placed, then when I right clicked on any block, a different block was placed. I also tried doing this process again, but a Lectern was placed.
Steps to Reproduce:
/gamemode spectator
Access the UI of a Smoker or Blast Furnace, then exit
/gamemode creative
Place a Cartography Table, it turns into a different block
Right click any block with an empty hand, another block will be placed
Try placing another one of the new blocks, it turns into a different block
I managed to reproduce this, but it's .. really weird.
I think the spectator mode rearranges the items in your inventory, so that the client and server go out of sync. It then places what was in the server inventory, but you see your new (broken) client inventory.
I would dare say this has nothing to do with the cartography table and is a bug in the spectator/smoker interaction.
original inventory
[media]spectator (see the change)
[media]back in creative
[media]placing planks with empty hand (the two blocks shown in the inventory place ghost blocks that immediately turn into air)
[media]