How to adjust for making candy from corn syrup instead of sugar?
This document seemed like it might answer your question as it talks about the temperature it takes to crystallize supersaturated sucrose solutions in the presence of fructose glucose and corn syrup.
https://www.researchgate.net/publication/242257775_Crystallization_of_the_supersaturated_sucrose_solutions_in_the_presence_of_fructose_glucose_and_corn_syrup
From what I know about candy making it is because sugar starts out as a crystal it can recrystallize after heating easier. With hard candy (glass candy) you're manipulating the sugars to reform the crystals how you want them.