Just a simple bug, if you cast a line into the water while a fish is in the way of where the line would go, the game simply renders the line behind the fish. Unsure if this is an issue with other mobs, only noticed it with salmon. Screenshot attached
-Duplicate of MC-166729 - please search before posting- err, didn't notice you specifically mentioned the fish, as an entity. Duplicate of MC-168311 then. Will be added to that ticket, thank you.