Triggered by some PSTAB misbehavior this morning we noticed that there was an oscillation at around 19 kHz on the PMC error signal .
We went to the laser lab to decrease the gain by 2 dB (now 5dB on the attenuation), the oscillation disappeared (plot).
The oscillation might be present since the works on the SL and IMC loop on the 11/03 but was not a problem till today.
The glitches are gone as well: see https://vim-online.virgo-gw.eu/resources/2025-03-28/resources/20250328_ana_plot_Hrec_hoft_16384Hz_freqtime.png.
