This problem has appeared with the update, I do not find out what this is about.
I do not know if this is related but I no longer have my 2 medium stand in my flight planner, just 3 small stand.
If you look at this picture, in -between the stands the area is not secure. What you have done is just zoned the stands and security checkpoint and exit as secure. (correct me if wrong!)
You need to zone the entire departure lounge as secure instead of just the checkpoints boarding desks exits and stands: