Indeed, the filter producing this channel was in an abnormal state. This was due to a too large change of the dynamic of the h(t) channel, due to weird h(t) values produced on April 8.

The filtering process has been restarted and the Hrec_hoft_20000Hz_Gated_500Hz channel is back.

The library version will be change during the Tuesday maintenance to use a more recent Fd version not sensitive to this kind of glitches.