Only apps that exits on the filesystem should be installable. No other category than "Enabled" and "Not enabled" should be shown. (Like in Nextcloud 10)
Many categories are shown like Files, Multimedia ...
All Apps from the store are shown.
Nextcloud version: (see Nextcloud admin page)
Version 11.0.0 (git)
Updated from an older Nextcloud/ownCloud or fresh install:
Where did you install Nextcloud from:
Thanks to @nickvergessen just a "return ;" in https://github.com/nextcloud/server/blob/master/lib/private/App/AppStore/Fetcher/Fetcher.php#L97 solves it.
I will create a proper PR.