Ok so I just set up a demo mode in Genie for your settings, so you do have a music program on the Xceed, set that up and then check for the distortion, if it is there, then it’s the loud input (80dB) level that you need to drop, for you most likely in the lower frequencies,but try all as well, I know you tried this in your other programs you had set up, but try this in the music program.
Just out of curiosity,do you have any feedback on the acoustics in you use?
Honestly if it were me, I’d start a new client and just to experiment a bit more on those lowest frequencies, which is where I think the distortion is.
Add your audiogram( the one in your picture not the in-situ fitting for now) …but don’t enter anything under 750Hz, then add only General ,DSE and music program.
Then check if the distortion is there, don’t do anything with the MPO, as this is not for speech or anything else, just the distortion issue.