Does it seem like your dog just doesn’t want to do what you want them to do despite having done the exact thing literally two seconds ago? Are they doing every other trick except the one you want?
Don’t worry, it’s most likely they’re just confused – and just as frustrated as you are. This can happen when your dog has gone through a long training session, having being taught multiple things at once, or they’re just not quite sure what you are asking of them and are doing as many things you’ve taught them in the hopes that one of those things is the one you want.
What you need to do now is to take a step back from your intended training, and return to a command or trick that they know 100%. This builds back their confidence, and allows them to “reset”.
Try the command/trick again after building up their confidence. Watch how your dog is responding. When it looks like their confidence has gone back up, have another go.
You will have better luck doing this than continuing to do the same trick endlessly.