How to prevent inconsistent comments in generated project config YAML files
Comments were added to Project Config files after Craft 3.6.8 referencing GitHub issue 7584.
They shouldn't be appearing and disappearing unless you're committing config files without them over the ones that already do have them in the repo. That being said, from my experience the comments are only applies to NEW fields added after 3.6.8, or at least are not all done at once as soon as you update to 3.6.8. To get around this, I'd do ./craft project-config/rebuild which will regenerate your config files and add comments to EVERYTHING, commit that, then get your developers to pull them.