Yes I have the same problem with mine. It wouldn't matter what treats I was carrying or if I turned and walked in the other direction. He wouldn't give a monkeys. I am using a long training line until I can get it sorted so that I can call him back to me and give a gentle tug in my direction on the training line and then when he comes back he gets praise and occasionally a treat. He's a lot better than he used to be but tbh I only really let him off if it's in field with no livestock in it and where I know there's isn't likely to be any other dogwalkers - which is not difficult round here as tis quite remote.

I hope to one day get it so that I can rely on him coming back every time but am a long way off that at the moment! If I'm going somewhere where there are other dogwalkers I keep him on a long lead but long term I want to be able to call him back to me if we come accross another dog and know for sure that he'll come back.

Will be interested to hear peoples suggestions too.