We recently experienced a bug with JVB stats. In fact, when we activate jvb stats for few hours we notice that the number of conferences is overestimated (70 conferences for 7 participants). I don't know if it's related but I think it's because of the clients timestamp because I get the warning below in jvb log:
JVB 2017-03-22 16:16:10.152 AVERTISSEMENT:  org.jitsi.impl.neomedia.rtcp.RemoteClockEstimator.log() Not updating remote clock because the timestamp point is invalid. ssrc=723617384, systemTime=Wed Mar 22 16:19:26 CET 2017, systemTimeMs=1490195966462, rtpTimestamp=1392872213, frequencyHz=0, streamHashCode=105612914
Have you every faced this problem ?