Ah it would have been cool for me to look at your log - I would have seen it was in Scheduler. I see what's happening. This is a buglet. But you must have ACP's Max Pointing Error set to a very small value? So after one of the images it stops orbital tracking and then does a tiny re-slew (0.6 arc min). The bug is that it doesn't automatically re-start orbital tracking afterward. It's probably lucky that the mount doesn't complain about being slewed with orbital tracking on.

For now, change ACP Preferences > PinPoint & All-Sky > Max Pointing Err to something greater than the motion of the mount during tracking of your 600 sec. exposures. I might suggest that with your 50 arc minute field of view, 5 arc minutes is enough pointing slop to allow it to just keep imaging. Another approach to this would be to put #nosolve into the Description field of your ImageSet. You'll need to do this through the Schedule Browser after you use the form. This will cause it to simply skip solving (and it's going to struggle with those streaked stars anyway).

I'm wondering if using orbital tracking should simply always disable final image plate solving (streaked stars)? Any opinions here? I'm tempted to make this a feature.