Time to change up the behavior. Giving you one claw can be made into a shake. So give your finger and gently shake. Once he gets it add the word SHAKE. Next let him give a claw...no reward and let him figure out what he does next. REally pay attention and watch as they do a slight head down and lean like they will step up. That should be a reward. Then go for a lift and reward. DO NOT move somewhere else until he gets this behavior. Sounds good what you are doing so far but it is time to move on.