GHS GB7CL Boomers 009 - 062

I've played GHS Strings for many years, but the sets I order recently (I always go for multiple sets whenever I place an order) all have the same issue:
Rusty plain strings.
On all the GHS sets (GBCL 6 and 7 strings, Gilmour signature sets G and F), literally ALL the high E, B and G strings have some black corrosion dotted all over the strings...

This doesn't seem to weaken them, but it certainly feels terrible, and it looks absolutely rusty too.

I asked GHS about this a few times, and never got a response....

So, I've now permanently switched to Pyramid Strings.