I‘d say its normal Gazrob, my previous dogs, who always had to stay in kennels (until GB finally decided to lift the quarantine regulations! ) and that was the homecoming I often got too, I used to feel quite offended!
, however I also agree with Mudmagnets, he could be tired. , If he‘s not back to normal in a couple of days though, it might be an idea to check with the vet that everything is ok incase he‘s picked something up.