On launching the game, the Mojang splash screen appears, then the game enters fullscreen mode, but shows what was on the screen between the window disappearing and the fullscreen window appearing. All of the buttons are still there, and can be clicked, but are invisible. Pressing F11 restores the game to windowed mode, but the frame contains an image of whatever was behind it when it was restored.

What I expected to happen was...:
I expected the game to show the Mojang splash, then enter fullscreen and display the main menu.

What actually happened was...:
On initially entering fullscreen, an image of the desktop was captured and displayed instead of the main menu, although all buttons were still interactable.

Steps to Reproduce:
1. Launch Minecraft in fullscreen mode.
2. Wait for the Mojang splash to disappear.

Notes:
1. This sometimes fixes itself by performing a forced quit so that the launcher reappears, then relaunching the game, with no other changes.
2. Reverting the default to windowed mode also eliminates the issue.
3. Entering fullscreen after the game has successfully launched and displayed the main menu also causes the issue to occur.