Hello TheRedHorseman,
Thank you for posting in the Apple Support Communities. We'd like to offer our support.
We understand that when creating a memory in the Photos app, Live Photos don't play as expected. Is the Live Photo the first image playing in the memory? If so, the title image might remain as a still image until the memory plays.
From there, check to see if other Live Photos play in other memories you create. For general information about creating Memories, check out the user guide below:
Use Memories in Photos on your iPhone, iPad, or iPod touch
If this appears to be with all Live Photos, regardless of where they appear in the memory, try closing the Photos app and restarting your iOS device. These steps might sound simple, but can resolve some unique issues.
Close an app on your iPhone or iPod touch
Restart your iPhone
We hope this information is useful. Kind regards.