I saw a glock 19 have FTE's every so often when my then 16 y.o. son would shoot it. His twin brother nor I had issues with it. After thinking about it I had him stop shooting it with one hand and use both only. (We were doing one handed shooting left and right hand). Anyway, problem went away and i still think he was limp wristing it as that same gun still shoots fine to this day!
...Although I "sold" it for $6.00 to my daughter in VA. She bought me lunch for six bucks and I couldn't bear to see her gunless when she moved. No worries, she was Army MP. ;-)