I have Labrador puppy who's coming up on 4 months and he used to do exactly what you describe. I too leave him in the kitchen overnight.

The way I got round it was by gradually increasing the night time. I started putting him in at midnight and getting up at 5:30am to take him out. Then I got up 5 or 10 minutes later each morning. Now he goes to bed at midnight, I get up at 8am and he's fine.

Good luck with it, he should get there in the end.

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