hi,
take your puppy immediately to the vet. take a blood picture
what are you feeding? Maybe change your food.
Is it still teething?
How is it at nights? Can your pup sleep without licking or does it lick during his sleep? Check out if it has to do with pain and your pup tries to compensate it by licking all the time.
And don't give him too much freedom. Where your dog is you are with him all the time!!
Do you have another dog or cats?
I really cannot imagine a rational reason for a behavioural problem, without further information.
lg
gs
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