They are grouped by Comment and Footprint.
It really looks like you just edited the description on one 0.47 μF to be 0.1 μF (or comment the other way), rather than also changing the description and value tags. I find it's a better way of working to actually replace one with another, as this avoids this kind of hassle.
You can change the grouping (by comment or value in stead of description) and that makes more sense in several occasions, or even turn off all the grouping. In case your Fab needs an itemised list with location and rotation for each component, for example. But it seems you have a whole different issue, that may keep popping up in unpredictable ways, until you actually fix the offending component, rather than fixing one symptom at a time.