Well, for one it depends on how he's developed. It might just be that he's not developed that well just yet.
Second, it could be that he needs time to adjust to the tactics. This is very much noticable in the game too. If you change tactics, you team needs to adapt to it. And also individual players. Give him as many pre-season games as you can.
I've never used the tactic so dont know how it exactly works (although I can make a pretty good guess seeing the formation). Looking at Bojan's instructions I dont think they are suited for him tbh. He's a great dribbler so he should definitely be running with the ball a lot. He'll skin defenders easily and score plenty for you. I'd set him on RWB often, FR often, LS mixed and the other 2 on rarely or mixed. But that might disrupt the tactics. Also, having him hold up the ball might not be such a good thing unless he has strength of 17 or above
imo. And also, in that tactic, you might have "use TM" ticked and Bojan is not the greatest TM tbh. Especially if the instruction is set to feed the ball to him on his head. If thats the case, dont change anything except for giving the ball to him at his feet and see if it works. Else try to modify according to the above. For that tactic you'd have been better off with Pato or Vela
imo. They're both strong and good in the air. Atleast better than Bojan. But with a little tweaking I dont see why Bojan couldnt be just as effective in that tactic.