sex and gender are best conceptualized as points in a multidimensional space
I can work with this.
Sex is a fixed point, or rather, one of two fixed points. Immutable.
Gender is usually, but not always, located around its matching fixed sex point. The distance can vary, and indeed, can change over time.
In some cases gender can ping out of our known, definable, measurable universe and enter a new-niverse of [bluehaired] dimensions.
I'd draw a graph but it might look a bit like boobs.