Scheduled Macros Randomly Fail to Start

I have a few macros that run every morning, but about once a week they all just don't run. None of them, and the KM logs show no attempt to run them.

The computer seems to be awake (it wakes on a schedule too) and most days they run fine. Just once a week, they fail to fire. (No, not on the same day. It seems to happen more on Tuesday or Thursdays, but I haven't specifically tracked it.) This is something that has just recently started. They all used to run reliably. Any ideas what could be going on?