I took the cover off one side of the harmonica so I could look at the valves. The sticking valves were not touching the Reed plate. Surprise, surprise! I thought the two layers of the valve must be sticking together. I put a slight Arch into the top layer of the valve, and that solved the problem.
-. You can Arch the top layer by putting a thin wire, such as a small paper clip between the layers, and then pushing down on the top layer where are the top layer is over the paper clip. I put the arch close to the end all the top layer.
-. I'm sure this won't solve all the sticking problems, but it solved my problem today.