Invisible leads

When I attach lead on rabbit and attach it to an wood fence in the air to looks like a real balloon and reload the chunks with f3+A I can't see the leads and I think they were removed. And when I remove the fence the lead falls from it. When I do it again I again can't see the leads. IS this screen bug? I use 960x600@60 (24bit) screen resolution for Minecraft 1.14 to play without crashing and maybe from this is the bug, but I don't know.