The Taz in siman 671:1 writes concerning how many menorahs to light in one's household, the Sefardim who light only one act in accordance with Tosafos and the Ashkenazim who light one for each family member act in accordance with the Rambam. The Taz calls this a novelty and ends off saying "this is something we don't find anywhere else"
ובכאן יש חידוש במנהג שהספרדים נוהגין כתוס' כמ"ש [ב"י] והאשכנזים כרמב"ם וזה לא מצינו בשאר מקומות:
Whether or not the Ashkenazim are actually only acting in accordance with Rambam or not, (see Mishbitzos Zahav who suggests since we light inside in separate places, we are acting in accordance with Tosafos as well), I am curious if there actually are any places where this flip has occurred.
Do we have any instances where Sefardim are obviously ruling in accordance with Tosafos while Ashkenazim rule obviously only according to Rambam?
Although there are other prominent Sefardi and Ashkenazi sources we can ask this type of question about, I'm limiting it to these two both to keep the question manageable and also because that is how the Taz started this whole idea.