doesn't sound like hes jacking at all too me , something has happened too him too make him come away , as the hard work is already done , you may have done too much too early , your only hope is too lift him now and try him next season , once they get into a habbit that's it , takes a lot too correct and the only way is too leave him off , maybe take him out on digs at the start of next season , listening too other workers , then giving him rewards , letting him know this is the reward under ground, ,ideally a few drains or culverts , start him off easy again . seen good potential dogs ruined