Yeah of course I can't find it now, there was some lame Youtuber memelord that let his buddy shoot at it with a handgun and at least one bullet went through. But I also see that it can resist it, so IDK and retract my statement.
I do know the difference between the calibers though, having shot a few different weapons in different calibers (as a hobby & in the military)
e.g., https://www.youtube.com/watch?v=vQ5EyKMqGGI
https://www.youtube.com/watch?v=hOteg0J5teg
Do you have links to those videos where it fails?
Besides, 9mm and .22lr are very different things. .22lr is one of the very weakest ballistic threats. 9mm has much more mass, usually more velocity, and a much higher (~3x higher) average KE load.