When using a texture pack that's greater than default (ex: 32x32 texture pack), the wire does not attach to the fishing rod stick. (Only visual misplacement.)
Every texture should result as a good placement of the wire.
How to reproduce:
Download the "Example to Show a bug.mcpack" provided, install it and then try using a fishing rod as shown in screenshot. The string should be misplaced even though it's only the default texture (doubled in scale).