On 2017-07-27, during the lock loss around 2 UTC, I noticed a sudden increase in kappa_tst from about 1.05 to 1.07. See the summary page for that day: https://ldas-jobs.ligo-wa.caltech.edu/~detchar/summary/day/20170727/cal/time_varying_factors/ It is likely correlated with the end reaction mass being moved at that time: https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=37800 LLO observed a similar issue, reported here: https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=31108
Plots showing changes in both kappa_tst and ETMY Pitch (at the same time).