In the last week, resonant condition between GR and IR changed by around 20Hz.

To check if there is any correlation with suspended mirrors, I checked the oplev signal of all mirrors. Basically all mirrors are staying in the same orientiation, but end mirrors have quite obvious drift during the last week. In fact, this drift seems to be not really because we are not really correcting it by the coils. So we need to investigate why end mirror oplev is behaving like this.