After performing a clean, there are often tracking files left. Only on a few occasions they are all cleaned.
Even cleaning several times in a row doesn't solve the problem. This issue exits for a while in different versions of CCleaner, always expecting that this would be solved in the newest update.
Don't worry too much about it, and it isn't a bug to be fixed, it's the way a computer works. - I'll explain why.
Health Check 'Trackers' - What they are.
These files are not malware which is actively 'tracking' you in the way most of us would regard 'tracking'.(ie. Getting your physical location and following you around, or logging your keystrokes, etc.).
CCleaner is not a virus/malware removal tool - It's a junk cleaner with some extra clean-up tools.
What Health Check calls 'Tra