On the PSL, IMC refl, ISS, and AS optical tables, the electrical ground (DC value) changed after the earthquake.
The largest reason should be the main laser stopping, but other effects might be like the May 5th earthquakes. https://klog.icrr.u-tokyo.ac.jp/osl/?r=25143
Washimi-kun also reported the change of the amount of water and Uchiyama-kun also reported the stop of the spring water at Y300.
So, we can expect a change of the water flow route in rocks around the KAGRA tunnel. This could be the source of the change of the ground resistance. and the change of the ground level?
footnote:
In my words "the main laser stopping" doesn't mean turning off the laser source, but it means stopping providing the laser for the interferometer.
In the magnetometer signal, we found long-term (~hours) glitches in the CS and the X-end just after the Earthquake.
