When you turn the clouds off the clouds starts to move with your crosshair... Displayed in the video
Edit: The clouds disappear when you hit ESC, press F11 (to exit fullscreen or enter) or reload the world
Environment
Windows 10 Pro 64bit
Java 8 Update 251
I had windowed mode on minecraft
GTX 1080
Thank you for your report!
We're tracking this issue in MC-186071, so this ticket is being resolved and linked as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
If you haven't already, you might like to make use of the search feature in the future to see if the issue has already been reported.
Quick Links:
📓 Issue Guidelines – 💬 Community Support – 📧 Customer Support – ✍️ Feedback and Suggestions – 📖 Game Wiki