Audio playback in Safari stops when device locked or Safari loses focus in iOS and iPadOS 15

In iOS and iPadOS 15.1, audio playback in Safari stops on certain web sites as soon as the Safari app loses focus (for example, if you switch apps, or return to the Home Screen), or if the device is locked. Sites affected appear to be any site playing an audio playlist, such as soundcloud.com and bandcamp.com that appear to use JavaScript or other code to advance from one track to the next. The device must be turned on/unlocked and the Safari app must have focus in order for audio to play continuously without stopping. This issue was not present in iOS 14, and appears to have been introduced in 15.

One well-known workaround available in prior versions of iOS/iPadOS to get the device to continue playing the Safari audio was to tap "Play" from Control Center in the top right after the audio stops. But, in iOS/iPadOS 15, once the Safari audio stops, tapping the "Play" button from Control Center does nothing, or the device may attempt to play music from the library in the Music app.

Here is a screen capture of the issue when listening to a playlist in Safari on bandcamp.com: https://www.youtube.com/watch?v=yKFTw6Qgl-Q (Notice how the audio playback completely stops and the playback card in Control Center is completely cleared once one track stops and before the next track can play)

The issue affects Safari, Chrome, and Firefox browsers on iOS and iPadOS 15.

I replicated this issue on two different iPhones running iOS 15.1. I also tested this on an iPad running iOS 14.8, and audio played back continuously when navigating away from Safari or locking the device. But, when I updated the iPad to iPadOS 15, the issue surfaced. Something definitely changed with Safari audio playback with iOS and iPadOS 15.

I reported the issue to Apple who escalated me to a few different reps over the course of a couple of days. I was told that unless a high number of users report this issue, it was unlikely that there would be any follow-up, but that it *might* be fixed in a future update.

Anyone else experiencing this? If so, I recommend reporting the issue to Apple Support to bring some attention to the issue so that it can be fixed in a future update.