I have had a bit of trouble trying to figure out why the lounge site says I am not eligible for non-Schengen lounge access (52) during my layover in AMS (DTW-AMS-OSL). The CS reps at KLM don't really have an answer for me.

I am wondering - am I not allowed to use the NS lounge since I am connecting to a Schengen destination? In other words, if your next stop is in Schengen, you can only use the Schengen lounge, and if your next stop is non-Schengen, you can only use the NS lounge?

Or should I be able to access both lounges freely? I ask only because I have a super-long layover, and I am trying to reserve someplace to take a nap while waiting. The Schengen lounge (25) does not have sleep cabins, but NS (52) does.

Please and thanks.