WO Creation with F3411

I am trying to create WOs using an import into the grid of P3411. Everything works fine except for a certain date for which it wont create an 'O' message. Looking at the table directly I see the message, but not in P3411. The date in shop calendar is set up as a workday and I am able to manually create a WO on that date. There is a shutdown planned in the calendar for several weeks before that, but I can't see how that would impact this.

Any ideas?

It's probably in F3412