tracker clearing

recently when running health check i have been advised there were a large number of trackers identified. i ran health check and only roughly half the trackers were cleaned this has happened twice recently. when i ran health check again i was advised there were only 17 trackers found when i was expecting there to be at least 80 given the number that had been cleaned previously. any ideas why this is happening

There are various reasons why files come back after cleaning.

With 'Trackers' (actually cookies and other browser files, history,etc.) syncing the browser can often be the cause, as can 'live tiles' on the start menu, and anything else that runs in the background.

See here for more about 'Trackers', why some files come back after cleaning, and what you can do to stop some (not all) of it: