Check to make sure that the app you are using is not being stopped by battery optimization.
To remove the app from battery optimization:
I have the same problem with spotify and the app is allowed to run in background .. i have tried everything
That is not the same as preventing battery optimization from stopping/pausing the app.
You can easily check this by comparing the list of apps under
Settings -> Device care -> Battery -> 3 dot menu -> Settings -> Sleeping apps
and the apps under
Settings -> Apps -> 3 dot menu -> Special access -> Optimize battery usage -> Select all from the menu which have the button flipped to the right.
I noticed the same thing on sirius XM, it will come to a pause randomly, then begin all of a sudden. Iv rebooted my phone, and un-installed and re-installed app, issue still occurs
1. Verify there are no settings within the app to cause them to pause or stop. 2. Verify the apps are listed under sleeping apps. 3. Follow the steps provided by @LongHiker to remove battery optimization. 4. Verify you have a secure connection to either mobile data or Wi-Fi. If the issue continues, you can take the phone to the nearest uBreakiFix location to be evaluated by a certified technician. https://www.samsung.com/us/support/ubreakifix/
I have had this issue for many years now, all the way back on my samsung galaxy s8+. Now I'm on the Note 10 and I still have this issue. I don't think it will ever get fixed at this rate lol
Definitely having this issue with Spotify for the last month or so on two different S9+`s. It will stop playback (playing a list of downloaded songs) then will start playing again either the second that I unlock the phone or after a random number of seconds on its own. No discernible pattern to it.