I have the same issue visit omegle
I don't believe they are double.
They are larger than 8 which is larger than 7 or 6.
There are only so many of them (1) and they only last so long (2).
8 and 9 tiles are all over. You have to check every area of the map, not just the center. And once gone, they're gone. An active kingdom will dive upon them as soon as KvK4 ends, so as to completely dry them out before any foreign order has a chance to do so.
At this point, late Wed., it should be no surprise that no n8 or n9 tiles remain anywhere in any k.