Well, at least it might catch some grit going into the engine. Never heard of greasing a choke plate but my ears are open.Meant white grease
As StarTech said, some carbs especially Chinese carbs might need some tweaking. Tooling gets dull and holes are not proper and so on.No you didn't do anything wrong. The problem is the plastic choke shaft in the carburetor is sticking. They do swell sometimes. The repair will require removing the carburetor so the choke shaft can be removed. Then using fine file or sandpaper rework the two parts of the that goes through the bushing holes of the carburetor just enough until the choke freely rotates again. Note don't over do it or get the shaft out of round.