The latest Apple flagship smartphones are facing yet another issue that means they do not work out of the box as described. This time, it seems that one of their dual speakers does not fire while playing audio. The bug has been reported numerous times on several different types of forum by now.
https://www.notebookcheck.net/Stereo-gate-iPhone-XS-and-XS-Max-hit-with-new-bug-audio-this-time.346041.0.html