Since a couple of months the filter of your deduplicate reporting tool has been changed, which results in about 1% of the duplicates in our CRM. It currently looks at the email address and looks at EXACT comparisson, rather than the combination of first+last name how it used to be. I don't know what the reason is for this, but the old way was way more convenient and easier to maintain.
the Hubspot system does the first level of duplicate reporting:
check first + last name similarities
Then the 'human' can decide whether it is the same person or not, judging the email address and other similarities.
Now I am manually spitting through an immense ammount of contacts and still find plenty of duplicates even though the report says we have none...