Why not let a qualified gunsmith (or authorized warranty/service center) inspect the revolver? Beats the possibility of an untrained person mistakenly thinking the symptom is the actual underlying problem.
Other folks have listed some possible causes of a cylinder being difficult to open/close normally. Might be one of them, and/or something else.
The cylinder bolt (to which the cylinder latch is attached) is a fitted part, meaning it's filed (at the front) to the proper length to function in any particular S&W revolver. Might be burred, too.
The end of the latch screw might be burred (or damaged) and dragging against the frame.
The cylinder pin might have a problem regarding its proper length, as well (for that particular revolver), or how it fits (or aligns) against the plunger at the front.
The ejector rod might be slightly bent.
The yoke (what another company calls a crane) might require an adjustment for it to be correctly aligned. Not something for the budding, untrained "kitchen-table hobbyist gunsmith" to attempt. It requires the use of the proper tools (alignment pin, lead babbitt and maybe a wooden wedge) to adjust (bend) the yoke barrel.
No reason to ever use a thread locker on the ejector rod, either. Really.
BTW, over-tightening an ejector rod can ruin the ejector, and maybe the extractor. Since the extractors are cut for each revolver using a factory tool (cutting hand/arm, sold to armorers), and may still require some small fitting for one or more ratchets (a specific type of file is used). It's another repair that shouldn't be attempted by the untrained "hobbyist". (Yes, as a S&W revolver armorer I've had to use the factory-made tool to cut and fit a few new extractors.)
Might be congealed sludge from an over-exuberant (and improper) application of lubricant at some point in the gun's history. Maybe some contaminant worked its way inside, too.
Recently, someone brought in a NIB M617 which wasn't working properly. Cylinder carry up and hand movement was not normal. When we removed the side plate we found that the hand spring had somehow slipped from its correct position. One of the spring legs had become caught between the hammer, trigger & rebound slide, causing it to become bent, and one of the spring legs had been "cut" off. Probably happened when the action was being worked with the spring out of its intended position.
Hadn't seen that happen before, myself. Weird. Production error? Dunno. Couldn't say. Installing a new spring of the correct type for that new style model (MIM hammer/trigger) corrected the problem.
No way to know what's happening with your
revolver unless someone familiar with S&W revolvers inspects it, though. Can't really diagnose a problem online, let alone correct or repair it.
So, as I mentioned, why not have it inspected by someone familiar with S&W revolvers? Why risk creating another problem trying to "fix" a perceived problem, you know?
Sometimes a well-intentioned owner/revolver enthusiast might find themselves in the unenviable and frustrating situation of having tried to "fix" a revolver until it's really broken.
Just my thoughts.