Titegroup should meter much better than that in your Lyman 55. How full is the reservoir? If you run it without sufficient fill (try at least half full as a minimum) and make sure you "vibrations" are similar each drop. Having it solidly mounted on a stable surface will make the vibrations more similar than if it is mounted on a surface prone to movement.
anything different than when it was working correctly?
have you checked your scale? (is the variation obvious when looking in the charged cases?)