Not all albums on Apple Music feature animated artwork, as animations are provided directly by the artists or record labels. If some albums animate while others remain static, it is often normal behavior, but specific settings can also restrict the animations.
Try this
Enable Animated Art: Go to Settings > Apps > Music, locate Animated Art, and make sure it is set to On(not Wi-Fi only if you are using mobile data).
Check Motion Settings: Go to Settings > Accessibility > Motion and ensure Reduce Motion is turned off. On some iOS versions, enabling Automatic photo and video preview under this menu is also required for artwork to play.
Disable Data Saver Modes: Check that Low Power Mode (in Battery settings) and Low Data Mode (in Cellular/Mobile Service options) are turned off, as these can restrict background video and animation loading.