Question:
What is the reason that some nusach Sefard shuls don’t say uvinu malkeinu on a fast day?
Answer:
This only by Nusach Sefardi, such as Eidot Hamizrach, but not by Chassidim who daven nusach Sefard. The reason they don’t say it, is because saying Aveinu Malkeinu is a minhag, and they don’t have this minhag.
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