May I respectfully suggest that when you are introducing a verbal cue e.g. SIT that you don't use the pups name.
By using the name in conjunction with the action e.g. Ranger SIT, The two words become the cue , when all you need is a single word [SIT]; using names is best used to get attention before you request a behaviour- e.g. pup walking away from you, you say their name: Ranger- as Ranger turns to look at you [paying you attention] call COME .