Last month we finally got a resolution to this after being persistent about not liking the change. It is correct, the Agent-ID was given a much higher weighting, in fact to me it has such a weighting that it ignores everything else!
We were seeing duplicates every time we re-imaged a workstation.
Anyway, I got a custom property from support to revert back to the old correlation algorithm. (THERE ARE KNOWN ISSUES WITH DOING THIS IF YOU HAVE VDI/CITRIX so beware).
The command to set this is “set custom property com.rapid7.nexpose.nsc.asset.correlation.v2=false”.
This saves to CustomEnvironment.properties in /opt/rapid7/nexpose/nsc/
Hope it helps, but do seek advise from support instead of just setting this!