Honestly, I think it's weird that the OP's Glock 19 doesn't cycle Blazer Brass. I've never had a problem with that ammunition in a variety of handguns, including out of Glock's, 1911's, XD's, Kahr's, Walther's, etc... I say this because for a long time about half the ammunition I'd shoot is Blazer Brass. It's pretty consistent ammunition. Is it the best ammunition? No. Is it the most accurate? Nope. Even Blazer Aluminum has been fine. The only brand of CCI in general that I have ever had real issues of any type with is Blazer .22 LR. It's perfectly fine in bolt action rifles (again not the most accurate), with 0-3 duds per brick. I don't shoot Blazer .22 LR out of semi-automatics any more because it is inconsistent and tends to be on the weak side.
Otherwise, 115 grain Blazer Brass should be right in a Glock 19's wheel house. It should eat that up.
I'm no expert on Glocks, but I'd guess that his Glock is slightly finicky because it is new. Maybe shoot some hotter 115 grains for practice and plinking for a while, like Fiocchi Shooting Dynamics. You can still get decent prices like $13 to $14 a box (try Midwayusa). It zips along at 1250 according to Fiocchi, which puts it into pretty hot territory for practice ammo. Just make sure you know the fps/ft lbs when buying Fiocchi. Sometimes they aren't labeled real well if you buy it in a brick and mortar store.
Blazer Brass isn't as cheap as it used to be, so I've been veering away from it to buy slightly higher quality Fiocchi or Sellier & Bellot. Magtech is also good and cheap. Or Speer Lawmen is quality, too--and by the way, they brag about having CCI primers...
Of course Hornady is good, but I usually won't pay unless I am doing target shooting or hunting.
Just about the only brand I would stay away from, oddly, is Winchester White Box. I've had numerous fail to fires/duds out of a variety of handguns and calibers with this brand. Other Winchester products are probably fine.
Anyway, this was way to long winded and aimless, but what I am saying my only real complaint about CCI Blazer Brass (centerfire Blazer, really) is that it is dirty and it isn't hot. But it seems danged consistent to me.