Meprolight Night sights

Part number: ML10224

These sights go on every Glock I own (Sans my 2 Gen 5's). I've been shooting with this particular brand of sights since I went to night sights exclusively (~12 years).

I bought 2 sets of these sights together just before Thanksgiving from the same store on the same day. Both are ML10224. 1 set went on a Glock 35 Gen 3 and the other a Glock 19 Gen 3. No issues with the 35 shooting from 5-25 yards. POA/POI are in the norm for me.

The 19 shoots about an inch high at 10 yards and off the paper (Center hold, dot covers target) at 25 yards. I ran American Eagle 124 and 147 grain FMJ as well as 124 +P Speer GDHP and 147 Speer GDHP. All with the same results. At 25 yards I need to hold almost at the bottom of my target (8.5x11" paper) in order to hit COM. If my math is correct that's just over 4 inches high at 25 yards.

Running my 19 Gen 5 with Ameriglo sights I have no issues and running my wife's 19 Gen 3 with the same exact Mepro sights I have no issues.

I measured the sights on the problem 19 and compared them to 4 other Gen 3 Glocks and they're the exact same height. I cannot discern any differences in the sights with my eyes.

Lock up on this 19 is tight with very little, if any, barrel movement. Brand new recoil spring. There's maybe 600 rounds through this gun as I normally carry a 17. It's an early model GYG prefix. All parts are OEM with a standard connector. Sights are the only aftermarket part. Installation of the sights was done by myself with all the proper sight installation tools.

Note: Because I carry a 17 most of the time, this 19 had the standard factory sights. I installed the Meps because I wanted to start carrying it instead. I did not have the POA issues with the factory sights like I do with the Meps.

What am I doing wrong and how do I fix it?