Question:
I drank wine of a mitzva before Havdalah and didn’t say ata chonantanu do I have to daven over? (Second night of Passover I forgot to be mavdil till after kiddush)
Answer:
Thank you for your question.
You do not have to daven shemona esrei again, because the knas for eating when one forgot to say ato chonantonu is only if the person was negligent. In your instance you were doing what you were supposed to do, say kiddush with havdalah. You forgot to say the havdalah part therefore technically you have to say it again, however regarding the knas it is considered like an “ones”, and it wouldn’t apply to you.
See the following post https://dinonline.org/2022/05/05/ato-choinantonu-and-havdolo/
Best wishes
