I'm running a recent, stable build of Moodle 3.5 on my website, https://www.onlinewithananda.org/yogananda-institute.
I can't access my site via the Moodle app. It accepts the URL, but when I try to enter my login credentials I get the warning, "Verify that you have correctly typed the URL and that your site uses Moodle 2.4 or later".
The app works with my dev site which has virtually identical configuration and database.
I am testing this on my Android phone.