The config component of xmlsitemap is never in-sync because it is re-acting to changes in content.
In particular:
max_filesize
updated
Is there a reason these values need to be included in config?
If they need to exist at all, is there a better place to store them?
Edit: These config values are stored in a site specific config file.
drush config-get xmlsitemap.xmlsitemap.NXhscRe0440PF…7u4e9aZwOM