Dedicated Server Grid size not working?

I set the following for the dedicated server:

// Grid size & number of slots reserved for players. Remaining will be populated with AI. 32 is the max setting.
"GridSize" : 15,
"MaxPlayers" : 5,

However, the server still ran with 25 racers, 5 human and 20 AI - though I set the server to only have 15 total. Where is the disconnect?

Thanks