Ok. Do you have any suggestions of how I could sort it out?

Without being at your computer and seeing your audio setup, it's hard to say.All I can suggest is taking a second look at your audio hardware set up.Best,

If you drop the complex 3d sound and just use simple stereo it will make sure users wont have any problems no matter what their system is. Having the FO come from the right is neat but not worth glitches like this.