Ibrahim and Sheila saw yesterday a lockloss after just 9 minutes in Nominal Low Noise from CSOFT_P ringing up at 1 Hz, and we again had one overnight at 05:21 UTC (can't link to online lockloss tool since it was down at the time). In both cases, the IFO had been down for several hours beforehand. After the ASC lockloss last night, the IFO relocked within an hour on its own and this CSOFT ringup did not; see first ndscope screenshot of the comparison between these two times. At the start of the third lock stretch overnight, after the IFO was only down for just under 3 hours, CSOFT_P did ring up the same amount of time into Nominal Low Noise, but this time it did not cause a lockloss and eventually calmed back down; see second screenshot. At the start of this lock stretch, after the IFO was down for under 2 hours, CSOFT_P did not seem to ring up at all; see third screenshot. This suggests to me that with a warmer IFO, CSOFT_P doesn't seem to ring up as much at low noise.

The history of this ringup and the last time we changed the CSOFT_P gain can be seen in alog85649. Sheila suggests if we see this ringing up again, we can try bumping the CSOFT_P gain up from 25 to 30.