Your GUESS about the cause for it carries no more weight than if 'god' did it. If you don't have an explanation, you don't have an explanation.

Some types of grease, when they don't have enough movement, will gum up, sludge up, and actually WILL do the opposite of what they're supposed to do. I hypothesized about garbage grease -- now I'm guessing the wrong type. (I've been using Slick 50 One grease for cables AND bearings since 2001, with ZERO problems.)

One final note: having built/repaired 31,000 bikes over a touch less than 16 years, I really don't need a lecture from an amateur.

But you do your bikes how you see fit. I'm out...C ya, wouldn't wanna B ya.