Taking, at face value, what ITTO has stated, it doesn't make sense for the guitar setup to be the issue (even though it sounds that way). Earlier this week, he said it had healed itself and was sounding normal, then it went bad again while playing. I don't believe a guitar setup could change that much during an hour or so of playing. He has also stated that he has tried several guitars and replaced the cables.
With pacocito's reamp of his Kemper DI track, this points to the guitar, the cable or the front end of the Kemper (the path for DI creation). Since ITTO seems to have eliminated the guitar and cable, it appears the front end of the Kemper needs to be looked at. It was stated earlier in this thread to compare a DI track created through the Kemper and a direct guitar recording without the Kemper. That's where I'd look since it is in the Kemper DI track. This test would very quickly determine whether it is the guitar/cable or front end of the Kemper.