It would not be the first or the last time that a glitch becomes the talk of the community Call of Duty Black Ops Cold War. From players who become invisible to characters who reappear on the other side of the map, the mistakes have become common in Warzone.
The latest sample of surreal errors directly affects the clouds which, as the user below shows, seems to grow and decrease at the pleasure of the player each time they aim with their peephole.
Luckily since Treyarch They seem to be quite attentive to the situation. They have a table of Trello in which you can see which errors are controlled and in which process. A good way to remind the community that they are still there to try to make everything as polished as possible.
In the case of clouds You may have also run into similar issues with other game effects like smoke particles, zombie eyes, or even uranium glitter.
It seems to be a bug with the FOV Xbox One and Xbox Series when it is above 80, so if it has also happened to you and you are waiting for a solution, reducing the FOV will end the problem.