The matting probably needs to be shaved out. A rabbit savvy vet can do this for you, but bring both buns.
You really have 2 options. One is to keep him clipped short. It doens't have to be very short, just so it doens't get matted as easily. The other option is daily brushing to keep the wool in good shape and trim out any matting as needed.
Some fuzzy lops don't have good coats to begin with and will mat easily. It is just part of having a rabbit with wool that they need regular brushing and clipping.
Since he is only 8 weeks, you do need to keep a close eye on them. Babies can change a lot as they mature, so fights can break out. Bonbon will need to be neutered once he is old enough and his testicles have dropped. If Gizzy isn't already neutered, that will need to be done as well. You might be able to get both done at the same time and put them back together once they are eating on their own.
