use peakmon, not BLRMS!
The ground velocity plots should overlay the PeakMon channel, not the BLRMS channel L1:ISI-GND_STS_CS_Z_EQ_PEAK_OUTMON and H1:ISI-GND_STS_CS_Z_EQ_PEAK_OUTMON These are designed to follow the velocity in realtime. the BLRMS monitors are not. See https://dcc.ligo.org/LIGO-T1900149 for a thrilling description.