I installed the cookbook app on the server and added a few recipes. When I log into the website on my iPad using safari I can see the cookbook. When I use the NextCloud IOS app on the iPad I cannot find any cookbook recipes.
It’s neither a bug nor a feature: The NextCloud iOS-App (as well as the Android App) supports mainly files and photos.
Other “Nextcloud-Apps” (like cookbook) are limited to the Website.