Having succesfully put into serial production 3 different type of AESA radar, China is not clueless when it come to radar programming. You would expect that by now legions of programmer in NRIET or other Chinese defense establishment who were well converse in radar programming.
You can count only 2 or 3 nations that can produce AESA radar. Russia until today has not put in serial production AESA radar!
True. I would believe that China had been quite well established by now in regards for the AESA radar's development and deployment.
However, lets off topic a bit, it seemed that many had been underestimating the Russian's capability. True they might not have put in serial production of the AESA radar, but that seriously doesn't means that they couldn't do it. There are many reasons behind, most of which we as outsider, would not know. What I can think of, however was -
1) It was not in the interest of the Russian to serial produce such a radar when they find what they have is adequate.
2) The Russian's military budget was not really very large, so they do not have enough budget to get these radars from their developers. (note that the Russian's economic model is no longer the same as in Soviet's time, and they do not have an iron fist in whatever R&D from private sector, so if the military had no money to buy, their private sectors will not sell.)
3) The Russian had something better under development that might be in various stages. We didn't know and couldn't see because radar in aircraft, unlike the entire aircraft, air intake and aerodynamical shape of the aircraft, was hidden in the vehicle itself and cannot be seen.
Now back to topic.