Timid Pup (Update)

I am by no means an expert, and I am sure that there are people on here with alot more experience than me but I do have a 1/2 curr 1/2 plott and he is the best dog I have ever owned. He is silent, wont catch and will run a fairly cold track. I have been breeding him for the past 2 yrs trying to replicate him with no luck yet. What I have found with this cross is that the pups are either timid or not, no matter how they are brought up. I have kept one for 2yrs waiting for him to turn on, giving him every chance. Before I got rid of him I would still have trouble catching him. So IMO if the pup is timid, you can either get used to it or get rid of it. I havent had any luck getting them over their timidness.