I wanted to check the last lock loss concerning the power upstream/downstream of the fast shutter, but quickly remembered that the upstream signal, i.e. the non-whitened analog version of the ASC-ASC_SUM, was disconnected from the fast PEM ADC (H1:PEM-CS_ADC_5_19_2K_OUT_DQ) before the last vent to fix OFI, and it was not reconnected since.
I went to the floor and restored the connection.