Totally normal from my end! I had much the same thing with DS. He always went perfectly while out but at home he was too lazy and uninterested in going to the toilet. I put it down to being a novelty while they are out. Also with the 30 second thing my DD did the same and I never knew if I should let it go or try and make her stay longer. Depending on how long it had been since she last went I either let it go or sang songs to encorage her to sit longer. In the end she got the hang if it It WILL happen! I figured I'd rather her get on the loo thousands of times than clean up wee all day long. At least it shows she knows what to do, kinda keep up the practice for the main event, lol. HTH