I would agree with Chris Z on the no lube in the firing pin channel. That will need to be cleaned out before you look to see what was wrong with it.
I am at 1st & O street, in Lincoln, Guns 2 Roses. I would be happy to clean it free of charge, and see what is out of spec, if anything. Number one cause of malfunctions in a Glock is ammo. First thing to check beyond basics on the gun, is try different ammo. That will cure the issue 99% of the time. Stick with the major brand names.
I was an FFL for years, retired in 2000 from selling guns. I am a Pistol instructor for NRA, teach concealed carry for the state of Nebraska and a Glock Certified Armorer. I own five Glocks of my own. Be happy to look at it for you, on the counter, in front of you, so we can see what is wrong, together.