Persistent negative peer scores in swarm

I am trying to diagnose a negative scoring profile on a test cluster. Per screenshot: cluster seems to be stabilizing on negative scores in a test run, and and max recorded score is zero.

Just to double-check my understanding, what the expected range of peer scores is in a healthy cluster?

Was able to confirm that expectation is positive score. I suspect this is being driven by common IP prefixes among nodes, but would like to find a way to verify.