Is it bad to use 'gender' to describe male/female?

When you're talking about biology, "sex" is the appropriate word

When you're talking about social roles, "gender" is the appropriate word.

You have a man, you have a woman. Then now you Heshes and Shehes with operations'. I guess that's about it.

What is the negative meanings to sex? 

On a side note, Zirp is an idiot. lol 

"Is it bad to use 'gender' to describe male/female?"

It isn't "bad".  It is what it is.  And what it is, has been morphed by social  justice warrior types to become a bunch of nonsense that has been used as a weapon of social shaming on the one hand ("this person misgendered me"), and one of legal harassment on the other hand (see the Jordan Peterson/Canadian government fiasco).

Since our corporate ruled judicial system is increasingly on board with these strange ideas based on critical theory (and not actual science), then the best way forward, at least in public, is to refer to people by SEX and not GENDER.  This way you cannot be guilty of misgendering someone.  Male and female are sex terms.  Man and woman are deemed to be gendered terms.  

Tread carefully now since cultural Marxists keep changing the language, and you can now be guilty of a language crime that can have you ostracized at the minimum, and jailed to lose your freedom ...which I'm sure we'll see an example of in the near future.

.

Well, if someone gets upset about this,it is their problem. 

I would say, just get a gun and shoot them as they are clearly the weakest link in human evolution, but this would be considered offensive too so I won't say it. 

Use whatever you are comfortable with. 

For me male/female is how you were born, otherwise I use transwomen. If someone has problem with that...with the truth that they were operated...that calls for another solution, maybe see a shrink or something. 

It is bad to write SEXE with just three letters.

There are two sexes, and some people are in between.

There are as many GENDERS as society acknowledges. If a person with a penis doesn't consider zirself male, or is only attracted to people who also have one, it's not my place to tell them they are as male as I am

Sex has negative meanings? I had no idea.

No.  You can describe people by what they are.  Personally I leave those who want to be something else describe themselves anyway they choose, but I still call and apple and apple and an orange and orange and a creature with a penis a male.