I have twelve CrossCores, and I’ve been using them for 3+ years each for 4-5 small group classes a week. Lots of use! I’ve never had fraying in the cable.
First and foremost, you should not be doing unilateral exercise (right left right left right left) with the pin in. Never drag the cable across a locked pulley. If you’re doing that, then yeah, you could damage your equipment. If you want to do unilateral exercise, pull the pin.
Definitely contact the company.