Losing keyboard events is well known by addon developers, particularly those making use of custom popups. Hence will manifest in different ways to users, depending on the addon, so might be hard to search for.
If you like you can disable the WASD capturing that's done by the CL650 in User Settings, and then bind the "move view fast" commands manually in X-Plane's keyboard controls window (to the same or different keys, readers' choice). This may alleviate the one source of "stuck keys".