Hello,
Not the first time a new m/c could have been defective. The rubber *cups* are easily damaged , eg. if you have itchy hands and push on the piston with the m/c dry, it can easily reverse the lip of any one of the cups or cause small tears.
This has happened to me with a new ATE m/c for another car, the supplier pushed on the end of the exposed piston to show me that it was not *stuck*, but when I installed it, it gave up after a week, the pedal would slowly sink and no amount of pumping would improve it.
When taken apart, one circuit main cup had a small tear, letting fluid pass thru.
I guess you live and learn.
At least you got around the problem, sounds like your indie is one of the *good guys*.
Take care and have a good week.
Oh, BTW, all you guys freezing right now in the US, it is 100F here today
