Pirate Map Farm stopped working?

[Chezus]

Hello Terrarians! I made a little farm for pirate maps. Everything worked perfectly on a older prototype, where I killed the mobs through the wall with a Dao of Pow. But then a friend said, that you can make a better, fully AFK-farm just by adding some bubbles and lava. I did that, and.. well, it's a afk-farm. I got some Jellyfish Necklace's, Yelets and even a Diving Helmet. But I never got any Pirate Maps. It has a pretty high drop chance and that's what confuses me.
Maybe some people can help me. :/

Here is a screenshot of my farm.

I'm thankful to every answer.

[Nova Solarius]

I think the issue is that your farm is a self-contained jungle biome. This is why you can get the Yelets.

Yeletses (?) drops from any enemy killed in a jungle biome. Pirate maps are much the same, dropping from enemies in ocean biomes.

It doesn't matter what enemy gets killed, only where it is when it dies. And enemies in your farm are in a jungle biome, not an ocean biome.

[Chezus]

Originally posted by Nova Solarius:

I think the issue is that your farm is a self-contained jungle biome. This is why you can get the Yelets.

Yeletses (?) drops from any enemy killed in a jungle biome. Pirate maps are much the same, dropping from enemies in ocean biomes.

It doesn't matter what enemy gets killed, only where it is when it dies. And enemies in your farm are in a jungle biome, not an ocean biome.

That's a good point. But I got this from the wikia, and everything worked perfectly before I used the lava. I even got one map, when I killed a jelly that was on one of the door sides with a summoner staff. Could it be, that Pirate Maps won't drop when enemies get killed by the lava? o:

[just.nuke.em]

I prefer using an artificial crisom biome in the ocean to spawn blood jellies.

[Nova Solarius]

Originally posted by JustDust666:

Originally posted by Nova Solarius:

I think the issue is that your farm is a self-contained jungle biome. This is why you can get the Yelets.

Yeletses (?) drops from any enemy killed in a jungle biome. Pirate maps are much the same, dropping from enemies in ocean biomes.

It doesn't matter what enemy gets killed, only where it is when it dies. And enemies in your farm are in a jungle biome, not an ocean biome.

That's a good point. But I got this from the wikia, and everything worked perfectly before I used the lava. I even got one map, when I killed a jelly that was on one of the door sides with a summoner staff. Could it be, that Pirate Maps won't drop when enemies get killed by the lava? o:

Possible. I'd continue searching if it wasn't almost 5 in the morning. Might I suggest using traps instead of lava?

[Chezus]

Originally posted by Nova Solarius:

Originally posted by JustDust666:

That's a good point. But I got this from the wikia, and everything worked perfectly before I used the lava. I even got one map, when I killed a jelly that was on one of the door sides with a summoner staff. Could it be, that Pirate Maps won't drop when enemies get killed by the lava? o:

Possible. I'd continue searching if it wasn't almost 5 in the morning. Might I suggest using traps instead of lava?

The problem is, I play in expert mode and the only traps I have are Dart Traps and Geysers and this takes forever.. :/
Still, thank you very very much for your help.