String doesn't connect when is above a block of Sea Lantern with regard to other blocks.

If you try to connect strings with a Sea Lantern block below and other blocks at the sides, you can't.

The Sea Lantern block has a different behavior with regard to other blocks, as you can see in the images below, the string stays a little higher than with other blocks.

But if you try with all three blocks of Sea Lantern, it works.