Why can’t I access my account through the app?
I’ve already created an account and paid for it on the website, and I’m trying to access it through the app, but it’s trying to make me buy a new subscription. Does anyone know how I can access an account that already exists?
Access through the app was spotty at best even before Musescore v4 . You may just have to wait a few days for someone to wake up and fix it.
See https://musescore.org/en/faq#faq-20657 and report that over on musescore.com