Options when Apple TV won’t stream and apple advice isn’t helping.

using Firestick in an older model Samsung, I can access Netflix, YouTube, and other services, but not AppleTV+. Have tried clearing cache and data, deleting and downloading AppleTV+ from the App Store, unplugging Firestick and the TV and reconnecting them, checking my ISP service with the provider; nothing will make AppleTV+ get past either the logo screen or the buffering symbol. Advice?