In most cases the stick is natural like many people have said. It's just the Ti gauling and sticking to the steel surface. Weird property of Ti, that is negated in the Sebenza by Carbonizing the lock to elliminate the ability for the Ti to gaul.
It will go away with time as the surface of the Ti becomes smoother on the lock interface and the small bits of Ti left behind everytime it stick form a layer that keeps it from happening.
If it persists, or becomes too hard to disengage, just put some graphite from a pencil on the blade tang where it interfaces with the lock. Sharpie is a bit more long-term method if you are concerned about the knife still doing it with the graphite, but you have to leave time for the sharpie to dry on the steel. Otherwise, just hope your thumb calluses quickly like the rest of us
And yeah, it is much more common in small folders for this to be an issue, but plenty of larger folders have the issue as well. Some of them can become impossible to close in some cases, and if that happens, take a falt-headed screwdriver, wrap the head in a soft cloth or tape, and use it as a pry-bar to open the lock, and then definitely apply either sharpie or graphite to prevent that from happnening again.
