Unisex names aren't rare nowadays in Israel; for example, they have Ofir, Ariel, Lior, etc... (see https://www.behindthename.com/names/gender/unisex/usage/hebrew/popularity/israel)Since it doesn't seem to be an error, I think that Immanuel, despite being a traditional masculine name, was recently coined as feminine. “Dear optimist, pessimist, and realist – while you guys were busy arguing about the glass of wine, I drank it! Sincerely, the opportunist!”-Lori Greiner