Gundogs shop for dummies (or game). They will try to fit two or more dummies in their mouths or swap between them when they’re supposed to be bring them nicely back to your hands.
So how do we stop this?
Like everything training related slowly. Don’t be scared to take a step (or two) backwards if you need to.
Start with your dog sitting steady while you throw two dummies 180 degrees apart. Send the dog for one, when they deliver to your hand go and get the other. Throw again and then go for one yourself and then send the dog. Next time get both yourself, then send your dog for both. Repeat this pattern of throwing dummies and retrieves as many times as it needs. Then repeat it again.
Now throw the dummies 90 degrees apart Send the dog for one, when they deliver to your hand go and get the other. Throw again and then go for one yourself and then send the dog. Next time get both yourself, then send your dog for both. Repeat this pattern of throwing dummies and retrieves as many times as it needs. Then repeat it again.
Finally throw the two dummies together. Send your dog for one and whistle them back. If you’ve done this slowly they’ll pick up one dummy and bring it back, without shopping. If they don’t then don’t be scared to step back, and approach things more slowly this time., You will get there