If you use Music Memos with iCloud, song ideas in your Library automatically update to iCloud. If some ideas look like they're continuously updating, your iOS device might not have enough storage space. You can use your iOS device to check its storage.
Go to Settings > General > Storage & iCloud Usage > Manage Storage. You'll see a list of your apps, and how much storage each one uses. For more information about its usage, tap the app from the list. Cached data and temporary data might not be counted as usage.
Depending on the app, you might be able to delete some of its content, or delete the app and all of its content. If your device is almost full and iOS can't free up space on your device, you might get a Storage Almost Full alert. If you see this alert, you'll need to manually remove some content.