Background activity using too much battery even when disabled

Hello, sunshinebml.

Thanks for posting in Apple Support Communities. We understand that you are seeing unexpected behavior in the battery usage section of your iPhone.

Are these third party apps or built-in apps? If so, which ones?

Which version of iOS is currently installed on your device? To check, go to Settings > General > About.

Are you able to determine if the background activity occurs while connected to Wi-Fi?

We look forward to hearing back from you. Take care.

Thanks for those details, sunshinebml.

Do you have iCloud Photo Library enabled on your iPhone? We ask as it may be possible that the background activity is related to photos uploading to iCloud.

For the background activity you see for Music, this could occur if you're playing songs/albums from the app, but your screen is locked or another app is open.

Let us know if these explanations sound reasonable.

Cheers!