Tripwire does not detect the fishing bob when it is in water

When a fishing bob is in water, the string above the source block attached to a tripwire hook does not detect it. This is wrong because in console and computer versions the tripwire can detect the fishing bob. Because of this bug we cant make afk fishing farms. But the string does not detect it only when it is attached to a tripwire hook. I tried testing it with only a string above the water and put an observer to detect the block update. The string could detect it everytime the fishing bob moved up and down. Tripwires only detect the fishing bob when the hitbox is touched.