I'm having trouble soldering sterling silver?

I am new to soldering. I currently do chainmaille and want to expand the types of jewelry I am able to make/work on. My next step is soldering. I have everything I need but am having a little trouble. I have an oxy/propane torch (Little Torch brand) and am using a #4 tip. I am making the flame bushy and about 3-4 inches long. I have only tried using the paste solder so far but I have strips of it too. I have tried both easy and medium and am having the same problem with both. I am practicing on jump rings and the solder is balling up on top of the seam and solidifies there. I can't get it to flow down. It is supposed to have flux in it already. Do I need to add some anyway? What could be my issue? Thanks for any help you can give.