Beste antwoord door Stijn NS
I have to agree with DDietzen and indeed say that the Sprinter should have been shown. If you search the same route last week or next week, you'll see the Sprinter is shown as a valid options, as well as the regular Intercity (not the IC Direct) that goes via Haarlem, Leiden & Den Haag. DDietzen is missing one more reason for why it's shown as it is right now however, which is that it's simply an error.
I've contacted the department behind the travel planner and we think this is a result of the maintenance work on the IC Direct route. For some reason, IC Direct serie 900 has lost it's IC Direct classification in the travel planner, due to having the maintenance notification. As a result, it is considered as a regular train by the travel planner, which causes other options that take significantly longer (Sprinter 1 hour 15 mins, other regular IC routes 1 hours 10+ minutes) to not be shown. I've forwarded the issue and hopefully it will be fixed later this week.