There is no cable break in period
. So, no it does not need to wear in. You have a clutch adjustment problem.
You may have an adjuster at the lever or there may by an adjustor section mid-way on the cable itself. If you do not see either of these, then there will be an engine adjustment. This can be anything from a lock nut around a slotted screw on the sprocket cover to an internal adjustment on the clutch side.
Sorry, but we just do not have enough experience with the Cosmos to be sure. Most of the smaller brands have a serious lack of technical information available.
Many of the smaller import brands (like Panda) use old factory tooling from major Japanese brands to create modern machines. Any experienced bike mechanic should be able to recognize it right away.
A Midwest dealer or local shop should be able to point out the clutch cable adjustor to you. It may even be covered in the owner’s manual. From there it should be a fairly simple fix.
We are currently working on a system that would allow users to attach photos to their questions, but until it is operational this is the best answer I have for you.