Long shot, but does anybody know why:
I listen to a podcast [*] via an external Bluetooth speaker from my iPhone while exercising. It's playing via streaming an MP3 in Safari. Often, not always, the sound simply stops after 5 minutes. I wake up the phone (with Safari front-most) and it starts again.
This doesn't always happen. I have listened without interruption for 60 or 90 minutes many times.
It may be happening more frequently (?). It only started recently (?).
Is this Bluetooth? Safari? Something changed in iOS?
[*] A History of Rock Music in 500 Songs by Andrew Hickey, https://500songs.com -- cannot recommend too highly.