This comes up every few months for the past 10 plus years.
Glock pistols when new have a habit of having pretty strong springs. The new recoil spring is strong. The new magazine spring is strong, with lots of upward force on the top round, which slows the slide down.
And then, people use what I call bunny fart loads, and are mystified when they have failure to extracts, failure to loads, and extractions that just dribble out of the ejection port.
The cure is 1) properly lubricate the gun before shooting it and 2) to break the gun in with hot ammo. Either hotter European spec ammo loaded to hot CIP standards (Italian made Fiocchi, for example) or to use some 9MM NATO ammo, or 9MM +p ammo. I GAURANTEE that had the video reviewer above ran 100 rounds of Speer Gold Dot 124 +P ammo, it would have ejected with authority and the gun would have ran fine.
I break in every new Glock I own with 200 rounds of 9BPLE 115 +p+ ammo (I have cases and cases). Remarkably, never any issues, even with new guns with new strong springs.
You can break the springs in by racking the slide a couple hundred times, locking the slide back when not in use, and loading and unloading the new magazines multiple times, and then leaving the magazines loaded for an extended period of time.
So in my honest educated opinion (former Glock armorer, 20 plus years experience, owned 50 plus Glock pistols) the Glock pistol in the video review above is probably just fine. It just needs broken in with hotter ammo.
Not sure who the Russian video reviewer is, but feel free to share my comment with him. He can run a part two video with hot ammo and I bet his gun runs perfect.
Some people will fault Glock for this but its really not fair to do that. Ammo manufacturers have neutered 9MM ammo over the years probably as a cost saving measure (less powder). They sell 9MM 115 grain target loads that are barely making 1050 or 1100 feet per second, when they SHOULD be 1200+ FPS for a 115 grain load.