can t drop T17 fortress

I was playing today to drop t17 fortress from dunes and other maps which should drop Fortress map, but after full juicing 20 maps i dropped 0 Fotress maps. I dont know if anyone came across the same issue or it was just bad luck let me know!

Not to state the obvious,

But check:

All voidstones socketed.

Atlas passive tree for map tier upgrade nodes.

Cartography scarab use.