A tire doing that at 300-400miles, without any abrading factor, is at the very least defective. Single strand, one time, I can understand; but a new strand after every ride is totally unacceptable.
I'll contact Schwalbe or the vendor who sold you the tire for a replacement (which they should be happy to do, so as to protect themselves against a possible future liability issue, and also to keep a happy customer who is smitten enough with this particular tire to be on set #3).