I am by no means an expert on this and will reply with my experience on a Swiss Army Knife I purchased at an online auction house. The model is not relevant, but, what you describe is very much like the problem I have had with the additional issue of the blades and tools being difficult to open and stepped or jerky when attempting to do so. My experience in the kitchen making candy and slicing sugary fruits such as apples some years ago and how hardened sugars can react to implements found in the kitchen may have been critical to solving it's problems. The first thing I did was to try to clean and lubricate the springs and joints. This helped some, but, it did not cure the problem. Next came a soak in warm soapy water followed by blowing the water out with an air hose, this was done several times. Then lube the blades, springs, tools and their pivot points. Remarkably, this SAK now open and closes as I expect it to.
The take away from this experience for me has been realizing that oil may have no or little affect on sugar contamination as a solvent as a person might expect it to. Also, the sides of the springs that contact the separation leaves need lubrication, not just the slip joint and hinge area. Pocket lint and debris can cause springs to become near non-functioning. And while I am here and this does not apply to this particular knife, there is a thing called dissimilar metal corrosion. This has to do with valence election migration from one metal to another in near proximity that are different materials. This may take considerable time, as in years, to materialize to the naked human eye. This corrosion is also known as Galvanic corrosion. More information about Galvanic corrosion can be found at this link>>>
https://en.wikipedia.org/wiki/Galvanic_corrosion
Edited to add: Non-gumming oils will help keep your springs functioning over the long term. If your oil does not mention it is non-gumming on it's label it is likely it is not non-gumming oil.