Hi @ExopackVFX,
Oof, can’t say I’ve ever seen this issue before.
The Volumetric Clouds are overall a very stable engine feature. I would try reverting any changes you’ve made to them / testing them out in a new project. I also recommend this because if you’re still running into the issue where they’re appearing in front of meshes, this is at least an easier problem to diagnose and thus hopefully fix.
If you’ve made permanent changes to any of the engine-provided volumetric cloud assets, you will have you either reimport them from another engine version or reinstall your engine to replace them with the correct files.