The bug

Animals follow players holding flowers, even if they cannot see the player.

This is a very interesting mechanic and might be intended.

To reproduce

1. Build an enclosure for an animal with pressure plates on the floor
2. Connect the pressure plates to redstone lamps
3. Summon an animal, such as a sheep, a pig, or a bee inside of the enclosure, so that it should never be able to see the player
4. Hold an item to lure the animal, such as wheat, a carrot, or flowers, and walk around
   → The animal will always follow the player, even if it does not see it

Video

Minecraft 19w34a 2019-08-24 13-23-49.mp4