I was AFK fishing with a newly enchanted fishing rod with LOTC 2, Unbreaking 2, mending, and Luck 2. When I woke up in the morning, the fishing was still going and after I checked my computer again in 10 minutes, I had idle timed out. When I loaded the realm back up, the fishing rod which I was holding was gone.

This was in Minecraft 1.16.4