The glitching occurs around 45 to 55 Hz.
I checked the ASC signal and the glitching around 45Hz is also shown in K1:ASC-DSOFT_P_OUT_DQ. The glitch around 55Hz is shown in K1:ASC-PRC2_P_OUT_DQ.
Is it related to this report (klog30951)?
Though this noise is the ETMY noise, it might shake XARM suspensionds through ASC loops.
Therefore, I checked microphone and accelerometer channels and found the same 55 Hz glitches appeared in these channels.
In other words, the sound of the compressor operating may have added vibration to the REFL table, causing glitches in the ASC control signal via the WFS.
Since the compressor will be stopped during the observation period, these glitches will disappear.