No obvious cuase yet, and no lock loss tool still. Oli noticed that the lights in the control room flickered about the same time as the lock loss, but we checked the H1:PEM-CS_MAINSMON_EBAY_{1,2,3}_DQ and end station equivalent channels and didn't see anything suspicious.
Back to Observing at 1827 UTC. Automated relocked, but we paused for 10 minutes Jim to swap an ITMY CPS card.