Video of the bug in action: https://youtu.be/o5tl-Q77EGE

If the player stands in one position for long enough, MCPE seemingly stops tracking the direction that the player is facing, affecting directional audio.

In the video linked above (stereo sound required), you can hear that although the sound of blocks breaking in-front of the player sound correct, blocks breaking to the left and right of the player are only heard in the left and right channels respectively.

The video also demonstrates updating player position. By taking a single step towards the right wall, audio now sounds correct while facing it, but the front wall can only be heard in the left channel. It only takes seconds for the bug to resurface.