When the fishing rod catches an item, the item does not reach the player as it normally does in other versions, it floats nearby instead. My fishing rod had lure 3 and luck of the sea 3 on it although the same effect appears with a normal fishing rod as well. After some initial testing it does not affect water 1 block deep (the item zooms towards players like normal) but with 2 block deep water (and I assume deep depths as well) the items move a little and then just sink. If the bobber is in the block next to the player then the player can pick up the item, but anything further than that, the item just sinks.
It is a little hard to capture the effect in screenshots
MC-125466
Fishing drops don't come towards player
Resolved
Fixed
4
Confirmed
Minecraft 18w07b, Minecraft 18w08b, Minecraft 18w10d, Minecraft 18w16a
Minecraft 18w19a
Retrieved
This happened before in 1.12 as well, and likely even before then. The problem is that the item spawns in too far down, or it gets pulled down when reeling in, and when it gets pulled in, it catches on blocks and seizes to move toward the player. It doesn't affect 1 block deep water because there are no blocks for it to catch on to. Try testing this again in a 2 block deep cube of water and the issue should stop. This is not a fix, it just proves what is causing the behavior.