For kits that's fine, for fresh grapes, most of the time .996 is not complete. I suspect at 28 brix and watered back to 25 brix, probably re-soaked back up to 26 or so, and the yeast gave up due to high ABV and low nutrients. Nothing wrong with that, it went far enough and tastes good. My point was just that there is probably sugar there and the yeast are managing to continue fermentation slowly, if you have time, let it go, in a hurry, move ahead and stabilize.