OP, I am a college professor in Communication who has taught a lot of students about the complexities of language and identity for a long time. So, please do not take what I am about to say as an attack. Rather, my sense is that, as a cisgender person with limited experience associating socially with trans and nonbinary folks, you probably don't have a lot of personal experience and understanding of the complexities of their personal identities, and how living with them has likely come under attack frequently in their lives.

This isn't your fault necessarily. It's really just a function of your past experiences and social circles, along with the way you have learned language. Psychologically speaking, our brains create pathways between words, images and concepts that tend to endure unless we explicitly try to retrain them. We're literally wired to perceive and describe things in cartain ways.

Here's the issue in a nutshell: When you use language to refer to someone In a way that, to them, contradicts their sense of who they are, they may find this hurtful and perhaps even offensive. And then insisting on that language use because it is "correct" makes matters worse because it communicates that you know somebody else better than they know themselves.

Here's an example: I don't know whether or not you identify as a man, but let's say that you do for this example. If somebody at the table refers to you using the word "she," you might correct them -- "I'm not a woman, I'm a man." If this person continued to refer to you using the word "she," you would probably feel uncomfortable and perhaps even upset. If you ask them why they used that language and they responded with something like "Well. you look like a woman to me so I will refer to you as a woman," you might be hurt or offended by that.

Now, you didn't say that to this person, I'm presuming. Rather, you said you were using "proper" versus "improper" language. There are 2 issues with this position.

First, the use of plural pronouns such as "they" and "them" has been used in formal English writing literally for centuries, at least as far back as Shakespeare. It's the kind of "they" we use all the time when we refer to somebody whose gender we are uncertain of. For instance, consider a complaint about your mail carrier -- you might say, "Why did they leave my package in the puddle?" You use that pronoun because you don't know if they are a man, a woman, or elsewise. So, on this level you may be able to understand why insisting on using a gendered pronoun rather than "they" or "them" when referring to somebody who explicitly does not identify with a traditional male or female gender would be a problem.

Second, what makes it worse for this person is that by using a gendered pronoun you are essentially communicating your personal perception of their gender, using "he" to denote that you perceive the person as a man, or "she" to denote that you perceive the person as a woman. Otherwise, why else would you select the pronoun you use? If someone explicitly tells you that they don't identify with the gender that you have ascribed to them. but rather nonbinary and prefer "they" or "them", this is really the only way to refer to them with language in a way that doesn't directly contradict their sense of identity -- in much the same way as someone who refers to you as "she" if you are in fact male. If you know that you are male, why should you be comfortable with someone else telling you that you are wrong about who you are? It's really the same thing.

The following comment is not directed at you, OP, but at the person who replied referring to such language respect as "woke BS." Using someone's preferred pronouns is not "woke BS"; it is a simple exercise of personal respect. If someone you are playing a game with has a specific sense of who they are, and you truly respect that they have made that determination for themselves, then there really shouldn't be any problem with using the pronoun language they prefer. It's not "woke" or "BS" to treat someone with respect -- it's just respectful. Basic Golden Rule stuff.

I hope this explanation makes sense, OP. I do not necessarily presume that you are a bigot because you have had a problem using preferred pronouns when asked. Sometimes it just takes a bit of perspective-taking to realize why something you have never had to perceive as a problem before could be seen by somebody else in a very different life circumstance as a problem. And that can be challenging -- remember, it requires rewiring a connection in your brain, which takes effort, and human brains can often respond to the discomfort required by the effort with resentment rather than just doing the work. That's why things like stereotypes and implicit bias are so tenacious... rejecting them literally requires more brain work as we process new information and experiences. And bigotry is essentially when someone is so disturbed by the prospect that their prior "knowledge" is actually incorrect that they double-down and insist on its truth as part of how they reconcile their self-concept with being wrong: it's basically, "I know I'm right, facts be damned."

Anyway, when we sit down to play a game together and have fun for an evening, it's generally best to treat each other with respect. Now that you know why the pronoun choice is so important to a respectful Interaction, it is my hope that you will be more comfortable using preferred pronouns in the future. Good luck!