He heavily saluki saturated and looks to have thrown to that side of the breeding more so than benji side, he may take a while longer to come along to full mental maturity, ie, looks like a man acts like a boy keep getting him out walking and lay off the quarry he bred for its a big ask this time of year for a young dog like sending a boy to do a mans job
Just get him out around the fields n moors let him learn himself and catch a few rabbits build some fitness and stamina , if it's meant to be the kill on chosen quarry will come but continual failure will dent his pride and put his head