MacBook Pro macOS Catalina 10.15.8,
Apple Music/iTunes Store sign-in suddenly stopped working. My Apple Account and password work normally on my iPhone and on the Apple Account website. On the Mac, I enter the password, the sign-in window spins, disappears, and I remain signed out. It then asks for the password repeatedly. Purchases made on my phone also cannot be downloaded to the Mac because the Mac cannot establish the Store login. This was working recently.