The only 'difficulties' in service has been on those when the CSD has warned us before the flight that they are now working 'one down'. Those when the CSD has just got on with their job as a professional have gone without a hitch. What conclusions do we draw from that?
That the CSDs in question are lazy, are incompetent, or want to try and show that this particular imposition doesn't work by sabotaging the service? (To name but three).