Fish overdepth, adjust the depth and shotting till you get it staying put.
Make sure you shot the float so only the bare minimum is showing.
Try a thin tipped waggler (long thin float attached bottom end only),less drag.
Try a longer waggler this creates more stability.
Fish with a finer mainline if you can get away with it, less drag again.
Up the rate you loosefeed the swim and fish on the drop recasting as soon as you feel that the hookbait has reached the bottom.
Fish with your back to the wind.
Try the lift method.These are all ideas you could try.