This is normal. Staff will take breaks in any zone marked "Staff Only" by the deployment menu. This might be related to why your behavioral guidance doesn't work. For some programs, prisoners cannot participate if they are not allowed in the room, or if they cannot reach the room without going through blocked security zones. Set your psychologist's office to "Shared" and see if the program works.
On the topic of staff breaks, however, I would like to see improvements in their AI. I like to build multiple staff rooms, so that they can use the nearest convenient one, but the staff likes to perform one activity at an object, and then for their next activity choose another object at complete random, even if it's halfway across the prisoner, even when another copy of the same object is right next to them in the same room. They ruin their break periods travelling. But that's off topic...
