With your first login to Fleet Health you might experience a lot of false positive issues (or no issues at all). This is likely because default calculation settings expect devices to behave in a specific way. However you probably have your devices configured differently than what the default settings in Fleet Health expect them to be.
The most common mismatch of default settings for a new account are the issue types ‘Data consumption (high)’ and ‘Data consumption (low)’.
If you want to learn to alter the settings yourself click the following link: Can I modify issue settings myself?