Question about string breakage

Playing with a head speed mp. Usually strung with full bed Lynx Tour at 52lb but decided to try Hawk Touch in the crosses. I usually break in the mains which makes sense because of the obvious notching and the spin in my shots but the last couple times I broke Lynx tour in the cross that looked frayed at the ends when it split. Today I broke Hawk touch in the cross and the string looks all flat 2 crosses above and below the breakpoint. Wonder if that happens at impact or the strings start stretching before they break? I’m confused what causes cross strings to pop like this