Hello, it's all matter of personalities but I have 2 males + 2 females living together and they all get along. I haven't even brought them all at the same time, they were gradually acquainted and at first, two females couldn't stand each other (they were living in separate cages) but after a while they all moved in together. Females tend to be really territorial and if you decide to have 4 of them, make sure to give them enough space (preferably in separate cages at first) and keep an eye on them to make sure they are not fighting.
It always depends upon the personalities of each individual bird no matter what the gender.
Some birds get along fine while others do not.
When housing mixed gender budgies in the same cage, it is important to have even ratios of each gender.
Additionally, when housing budgies of mixed gender together, you have to be aware of the potential for breeding and do everything possible to discourage that.