I had a broken stantion I welded. Used the same grinding wheel
on the ss as I had used on some mild steel. Now the weld looks all rusty. Mild metal flakes from the grinding wheel
on the stantion are rusting.
OTOH, what you have would worry me. I'm surly no expert, but that would sort of indicate to me there was a problem with the wire. Especially since it is so consistent.
Once many years ago I had an incidence where some control cable had a manufacturing problem that caused it to fail if it was pulled too tight in the installation
. It was a mechanical issue with the cable production machinery. I was able to convince the manufacturer that it was his issue. It was a bid dollar problem.
Pretty irrelevant to here other than stuff does happen.