After upgrading to DLP 15.7 MP2 incidents are no longer being detected. You will see the following in the Detection Trace logs.
This is caused by a failure of the Windows installer package to replace existing DLLs with newer versions that lack dependency on a legacy runtime studio package.
DLP 15.7 MP2
A new package for 15.7 MP2 has replaced the old one, and is published at the Download Portal.
The new package contains a required hotfix for customers who have installed 15.7 MP2, which will apply the updates necessary to remove dependency on the legacy runtime package.
For details, see this advisory: DLP 15.7 MP2 Required Hotfix for Windows.