They both need to be neutered — hormones are invisible and it’s impossible to predict when and how either rabbit will react to one of them still being intact. Also, both rabbits are still young, so the likelihood that the other rabbit will act more on hormones as he ages. Any relationship that includes at least one intact rabbit is considered a ‘baby bond’, which is what you experienced earlier. It is a bond that is seemingly wonderful; however, upon one acting on their hormones, it gets hostile quickly. The baby bond is dissolved so both rabbits must be neutered, one-month post-recovery, and then you need to go through the proper bonding process: https://binkybunny.com/infocategory/bonding/
Also note, depending on how they’re housed, the presence of any non-bonded rabbit (i.e., the female I believe) can trigger territorial aggression in all other rabbits, regardless of fix status. Your clothes, hands, etc. can smell like a non-bonded rabbit and that can trigger a different rabbit to become aggressive towards you. Rabbits smell and hear first; not see, so how you smell is going to be much more indicative to what sort of “threat” you are than how you actually look (similar to how bonds can be broken when one rabbit goes to the vet and returns smelling different).
Also, note that a baby bond is not a true bond, so do not feel terribly guilty for separating them for this time — it is for their safety and their bond is not stable/secure.
The answers provided in this discussion are for general guideline purposes only. The information is not intended to diagnose or treat your pet. Seek the advice of your veterinarian or a qualified behaviorist.