I tried the solution of activating Apple Music, that I have 1 free month, as suggested to fix and and worked. But after I cancelled the subscription, and the current song finished, the issue came back.
I have a iPhone 13 Max. There is a way to permanently fix it?
iPhone 13 Pro Max, iOS 15
Hello ShaidonKaos,
Thanks for choosing the Apple Support Communities. The Autoplay feature can be turned on by following these steps:
"Let Autoplay pick what plays next
Autoplay takes the work out of choosing what to play next. Just play a song, then Autoplay finds similar songs and plays them afterward.
To see your Autoplay queue:
.To turn Autoplay on or off, tap the Autoplay button 
in the upper-right corner of your screen. If you turn off Autoplay on one of your devices, then Autoplay is turned off on any device that's signed in with your Apple ID."
More info can be found here: Add music to your queue to play next on your iPhone, iPad, iPod touch, or Android device - Apple Support
If the icon is not showing, restarting the iPhone may help resolve many issues.
Restart your iPhone - Apple Support
If those steps don't help, let us know what version of iOS you're running and we'll go from there.
Cheers!
Hello ShaidonKaos,
Autoplay is a feature that is available to Apple Music subscribers and you can read more about that here:
If you would like to submit feedback to have this feature included in iOS without a subscription, you can submit product feedback here:
All feedback is reviewed and this provides our teams with valuable information about what our customer's want to see in upcoming releases.
Take care.
My issue is not how autoplay works, but how the icon is not showing. And yes, I restarted my iPhone plenty of time. Believe me, I read a lot about this issue, including a few of topics from here, and tried to fix it.
My only device that have music on, that is my iPhone, is using the last update that is 15.5 (as shown at the software update menu).
And I'm going to repeat, the autoplay (infinite icon) appeared and worked while I was subscribed to Apple Music, then disappeared again when I cancelled the subscription. I don't have interested in the Apple Music feature.
If that basic function of allowing me to play one song or all, is exclusive of subscription, that is just nonsense!
That is like removing the locking mechanism of a bathroom door, because I'm not paying the month. I can still close it, but I'll have to trust to anyone else of not opening it.
The auto-play button is missing at my music app! (infinity icon)
