Not much help from the JV desk Try to arrange it directly with the operating carrier, KLM.
Same issues in the past with KLM when booking those EC seats. They didn't recognize my status. Called KLM, they are able to 'overrule' the system and put pax manually in those seats.
Secondly sometimes i didn't call and paid full price for those EC seats....always got a refund by again contacting KLM directly.

If you fly back with KLM try to also arrange the seats for that return trip in the KLM lounge tomorrow.