Passion Vines incorrectly check the light level at the block position above them when checking if they can increase their "age" state. This causes the top block of a passion vine to not be able to flower or grow passion fruit if there is a light-blocking block above it. This can also prevent the vine from being able to grow more passion vines downwards if it was not already flowering before blocking the light above it.
Passion Vines incorrectly check the light level at the block position above them when checking if they can increase their "age" state. This causes the top block of a passion vine to not be able to flower or grow passion fruit if there is a light-blocking block above it. This can also prevent the vine from being able to grow more passion vines downwards if it was not already flowering before blocking the light above it.