Take an actual gravity sample with degassed beer using a hydrometer. Your RAPT pill may have krausen crud stuck to it throwing off the reading. My conclusion for these sorts of devices is that they’re useful for monitoring temp and letting you know when your fermentation is completed but the measurement of FG is probably inaccurate.
You can dump the oxidized portion, or add some vinegar mother and try to make it into wine vinegar. I’d just let that stuff go and enjoy the bottles that turned out well.