Big shy Largemouth Bass

I am again looking for advise about shy Largemouth Bass. One of the small three acre ponds that I fish has huge Bluegills and a good number of bass. Some of the bass are in the trophy range. Lately, as the water warms, I have been catching some massive gills. On at least five occasions this past week, while bringing in a big Bluegill, a huge bass has made gigantic swirls swiping at the gill. They hit and almost grab the big gill but not quite. I have tried hollow fleyes of the appropriate color, clousers, bucktails, feather wings, shad immitations. Sinking. Floating. Slow. Fast. Dahlberg Divers. Pig boats. Please send help!