[LWJGL2] After ungrabbing a grabbed-mouse, it remains invisible

In my first person shooter, I've noticed a strange issue with Mouse.setGrabbed( false ); after the mouse was previously grabbed.

In my current project, once I ungrab the mouse, it does not become visible. However, it can move around, and it does function normally. Once the mouse leaves the game window, it becomes visible. When it re-enters the window it is also visible.

I've opened some old LWJGL projects on my computer and this happens with them as well.