Adam Pace

I've had this for a very long time now and I thought some more information can help you solve it sooner. It is on any multiplayer server and can happen with any item entities. This includes droppers, killing a mob, breaking a block, saplings from trees, and anything else that makes entities. Happens around 90% of the time and I've found it has nothing to do with how many people are online.

this hasn't been resolved.

I also experience this issue in realms. Most the time when a block is destroyed or anything is dropped, the item is not shown on the floor and acts like it is invisible. When a "visible" item links with an invisible one they both become invisible, and sometimes both become visible. When a block such as coal ore is broken, the xp orbs will drop as normal, but the coal will be invisible, but still able to be picked up. It looks as if you are breaking stone without a pickaxe.

This is happening in my realm, and happens about 60% of the time. Sometimes the items that drop from the block will link with an invisible one, and both become invisible. Sometimes the invisible one will link with a visible one and become visible. Same happens when anything is dropped.