Are my relatives just stupid? (AUH)

I gave in and bought AUH, and it is the best DLC they've released since T&T.

One problem, though:  

The older of my two half brothers came of age and I gave him a province to govern once I got a duchy.

Now, 14 years later, he has absolutely refused to give it up to take the local exams. I'm now the ruler of the 3rd most prominent circuit in China and the liege of his liege, and he still refuses to give up his single county to take exams that will let him become a higher ranking official. I even hosted my own local exams, twice, specifically to pass my sons through, and he still refused to attend.

That process has now repeated with his younger brother. He is also a count who refuses to give up his position to take even the basic exams.

The best I've managed to do is confiscate their children and send them through the exams. My two sons, their two cousins, and my grandson have all passed their exams and gone on to be mid-level bureaucrats with titles of their own.

Is this an AI bug where it tries to hold power and refuses to give it up even for higher power, or are my relatives specifically just stupid?     (AUH)