Finally found one: https://meaningcrafters.com/produit/powerbank-alex/
I don't speak French but placing the order was quite straightforward. Shipping costs were a bit high, but totally worth it. Highly recommended!
Phone cases by Mobiwear are Made in Poland. I have this one for another phone model: https://mobiwear.de/product-ger-236894-Hulle-fur-Samsung-Galaxy-S22-Farbe-Schwarz-mit-Schwarz.html (Sorry, website doesn't seem to be available in english. But look around, the cases are also available elsewhere.) I've been using it daily for almost 2 years and it still looks and feels almost like new.
You're right to be sceptical. I've learned to not blindly trust the "Made in Italy" label for example. But this website reads (translated with https://www.deepl.com/):
So that's good enough for me.