There are several possible issues that are causing the cylinder to be difficult to release from the frame. The most common, and the one I would check first, is that the ejector rod is loose. You can take a small pointed wooden or plastic rod (stay away from a metal object to prevent scratching the piece) and insert it between the tip of the ejector rod and the pin that holds it in place. Once there, pull it gently backwards (towards the grip) while at the same time pushing the cylinder from the right to the left side.
If this was the cause, you will then need to tighten the ejector rod. You will do this by placing at least 3 empty cartridges in alternating charge holes in the cylinder, and then gently tighten the ejector rod by hand, and follow up with an appropriate tool. I like this one - the Vicesmith, but a drill chuck from a hand drill will also work:
ViseSmith™ - a unique extractor rod tool for - S&W(R), Taurus(R), and Ruger(R) Speed Six Revolvers | Welcome to Gunsmither™ Tools | Myself
Please post again if this doesn't work, or consider sending it either back to the factory or a qualified gunsmith.
Good luck,
Dave