All AI planes are being set to rwy 16. I seem to be the only one that's not so thats why Im confused as to why I am the only one.
That is very odd. PF3 looks first at AI traffic to determine which runway to assign you. If no traffic is active it will use the wind direction to determine.
PF3 should have used 16 also, you have not "closed" the runway in PF3 options have you?
If you are using a weather engine, I suggest ensuring it is updating and then refresh AI aircraft before connecting PF3. I often find that when I first load the sim it can take a minute or so for the weather engine to update, and in the meantime AI aircraft will start to taxi to the "active" runway based on a no-wind scenario. It can take a while for this to correct. If in the meantime you connect to PF3 at a moment where there is no AI movement it will determine runway use based on the wind even though previous traffic have been using a different runway. Refreshing AI traffic once your weather engine is online keeps everything in sync.