Rekordbox Subscription Issue: Repeated Prompts on iOS and iPadOS

I am already a subscriber of rekordbox, but on iOS and iPadOS, every time I navigate to a new screen and then return to the advanced features, I am repeatedly prompted to subscribe again. Even after entering my Apple ID, the issue persists—accessing other pages causes the subscription request to reappear. I also noticed I can only use my Apple ID to log in, not my existing subscription account. Why does this keep happening?