You didn’t mention if there have been any recent changes in their housing or living conditions or other people or pets being in the house. If that’s not the case, then they probably need to go through proper bonding.
Even though your rabbits are related, you still have to go through a bonding process. A baby bunny will temporarily bond with other babies or with an adult, but once they both reach puberty, they should be separated. Then after their surgeries and a few weeks or month has passed, you can start the bonding process. If Lala and Charlie have never been apart, then they are likely not really bonded. The best thing to do would be to separate them now, keep them in the same room, but house and exercise them separately, then in a few days or a week, start the bonding process in a neutral space. If there aren’t any rooms in your house that are neutral to them, you could still set up an x-pen in any room, with a sheet under it to mask any scents, plus wash down the pen if needed. I use the x-pen method. My husband and I get in the pen with them, to stop any fighting (some scuffling is normal) or stop any excessive humping. We start with a few minutes the first day, then increase the time each day. There are other methods you can use too.
Here are 2 articles on bonding:
http://rabbit.org/faq-bonding-multiple-rabbits/
https://binkybunny.com/BUNNYINFO/tabid/53/CategoryID/9/PID/940/Default.aspx
I realize that your rabbits have been together since the birth of Charlie, but in order to ensure the best possible permanent bonds for rabbits, you do have to go through a bonding process.