Riva 510 is usually 750mah+ and the Liberty-Flights.com current ones are higher voltage than Ego at 3.7v. It is not a slim 510.
OK - so this is a clear dual coil? They are very new. Do they have stuffing? Or empty with dangling wicks? If the latter, sometimes a wick can be caught in the inner seal - in general clear cartos are for tinkerers with patience. Sorry I only know stuff about CE2 clear cartos, never seen the Smoketech dc clears. Clear no-stuffing cartos are usually filled with a blunt syringe through a specified spot.
If they are clear and have stuffing (would be odd but I have not seen them) - looking damp is not the same thing as being fully damp. With stuffing cartos you need to know the full capacity of the carto, and I make it take at least 18 drops per ml of capacity, then wait 15-30 seconds, then add how ever many more drops will easily soak in (while I hole a tissue on the threaded end hole). Then I clean up, blow out the central air channel (blowing into threaded end with open end down toward a tissue, and while the open end is down I touch a soft bit of tissue to the top of the stuffing to sop up any loose juice. Then it has to settle. I lay the carto on different sides for 15-20 minutes to make sure every bit of stuffing is damp. I use high PG juices (80PG/20Vg or less VG) and that is enough time for my thin high-PG juices. With dual coil stuffing cartos I think people use a syringe for at least part of the first fill.
Hopefully someone can help you with these. They are very new. Meanwhile, try some Boge cartos. They are the most popular cartos on 510-threaded devices because they just work.