Are you putting silicone grease on the seals every couple of dives? I find they are very difficult to get snapped on properly when I need to re-grease them, but when they have been freshly lubed up they snap right on and give a nice convincing click like in the video (link below). When they are in need of more lube it's more difficult to get them on and they don't give that nice click that lets you know they are sealed. I just use a little tub of silicone grease that I keep in my dive bag every couple of dives.
Another thought - when you installed the dry gloves did you make sure to trim off the excess from the glove so it's not interfering with a good seal? I had to install mine
watching the video. Dry gloves are cheap. I ordered a pair of each of these brands and they all seem pretty similar (like dishwashing gloves but thankfully black). Do be careful when trimming the excess glove to keep your cut exactly parallel to the cuff. These gloves will tear easily up into the body of the glove if you are hasty. I ruined one that way when installing it.
Ansell
Mapa
Showa
Maybe install a new pair and make sure it's not the installation that's causing the leak?
Since I started lubing mine up with silicone grease, I haven't had a leak except when I put a hole in a glove (I think). Oddly I could not see the hole, but it leaked even when I put the suit in the bathtub. I swapped out the glove and it no longer leaks.
I hope you can get yours working well. I have no experience with other systems but I love having dry gloves. Especially since I get leaking around my wrist tendons when using wrist seals, the dry gloves have made cold water diving much more pleasant for me.