Hi there,
Were you able to get this issue resolved? We are experiencing a similar case where the ad agency who uses Google DCM is reporting highly inflated ad click throughs compared to our internal Adobe Analytic's tracking code instances or campaign view counts.
I see that "Gigazelle" recommended checking the allocation and expiration rules. But aren't they for visits and page views attributions to a tracking code and shouldn't the actual ad click through counts remain same irrespective of this? Please advise. Thanks in advance!