Items (maybe other entities) are invisible when near the edge of the screen on Quake Pro FoV

In Quake Pro, an item (coal) at the edge of the screen became invisible

What I expected to happen was...:
Continue to see the item

What actually happened was...:
The item was invisible

Steps to Reproduce:
1. Switch to the FoV Quake Pro
2. Throw item on ground
3. Turn so that item is at the edge of screen
4. Item disappears