I appreciate that. I find the same thing happens on all 3 of my 6 strings on the high C. I've checked for sharp bits on the saddles and can't find any. I think I probably play too hard, or at least pop the high C too hard, but that's because I get carried away and there's not a lot I can do about it (other than getting better, and that's not going to happen! )
The high C from that Newtone set is still intact after 3 years, if a little dead