Account search does not work unless you have authed via MastoWeb
You cannot search for users unless you have successfully authed via MastoWeb. The PleromaFE auth is not enough. This affects Mastodon mobile apps and restricts their ability to search.
e.g., https://yourinstance.org/api/v1/accounts/search?q=someuser will return a 403 unless you first login to /web/ and try again.