there is no repair for this, the only way to fix it is a new panel. I will try to convince the guy
I have three Kuros (5080, 500M, 600M), two with heavy usage (5080 and 600M), and no sign of red whatsoever. Out of hundreds or more Kuro owners here, maybe a half-dozen have complained of this.
Also, I have no idea why complaints about a possible technical problem are being aired on this thread in the first place.