Ed, Patrick and Jenne
Apologies if this is a repeat, but I've never seen this and was at a noticeable loss for action to take.
After the Lockloss at 23:30UTC, there was a diag main message that indicatd that ISC_LOCK wasn't going anywhere until the Fast Shuttter was tested. I'm making a Wiki in Troubleshooting H1 to address what to do in this situation. Jenne came to the rescue. Thanks Jenne!