You are contradicting yourself, if the alarm was triggered when making dinner then it must have generated a smoke, how would the detector even know you are making dinner.

With the nest, the alarm turned by itself for no reason, you don't cook in bedroom, he even said that he got notification when he was at work.

Two different reasons, your situation was that smoke alarm was too sensitive, perhaps you placed it close to the oven, here the alarm fires for no reason, and it is not the kitchen one, but bedroom one where normally you don't have smoke.