Slitherine

I thought I understood troop movements, but this doesn't fit.
I am playing Dragonhold, fighting the Iron Barony of course. You may have to refer to the map for this. I hold with armies in place, Splitter Pass, Dead Mine, Mirak's Run, and Raker Way. I thought I could not be invaded at Splitter Pass, but it was done, from Kom Fang, bypassing my troops there. According to my experience, the Army at Raker Way should have blocked that move. Is this a bug or do I not understand the rules?

It does seem to be a bug.. There should be no direct connection between Splitter pass and either Kom Fang or Dead Mine, so the enemy would have to use another adjacent province to get there - Could they have gone around through Ferroscar maybe though?