Praise be to Allah.
The described behavior in the question is scientifically known as "feminine bodily/physical expression," and the truth is that feminine bodily expression does not necessarily relate to sexual orientation. Often, it is a natural part of a person's character, and sometimes it is due to limited interaction with males. However, to judge that this is an expression of a deviant sexual inclination or a disorder in sexual identity requires more evident and deeper considerations.
If we assume that the description is accurate and that the boy indeed exhibits feminine bodily/physical expression, we must deal with the problem within these limits, without undue fears. Excessive fears may lead to incorrect methods of treatment, especially since, as described in the question, these feminine expressions are few. Therefore, we fear that the apprehension may affect the accurate assessment of the situation.
One of the incorrect methods of treatment is to alert the boy to change his bodily/physical expression, as this actually produces counterproductive results. The correct approach here is to ignore the matter in terms of not alerting the boy, not in terms of avoiding the correct methods of treatment. The intention is to avoid drawing the boy's attention to the issue, as this exacerbates the problem and confuses the boy. However, we will pursue the correct methods to address the matter.
The correct methods of treatment are based on creating a masculine environment for the boy to interact with, and suggestions for such an environment include:
1- Connecting the boy with a Quran memorization group or a Shaykh who teaches him and establishes a relationship that makes the boy emulate him.
2- Enrolling the boy in masculine sports, such as martial arts.
3- The boy reads stories about the Companions, especially the knights and warriors among them, and then you ask the boy to present these stories in the form of a play, making this a regular activity for you.
It is also beneficial for the boy to memorize a significant number of these inspirational sayings from the heroes of the Companions, especially in situations of jihad, battles, sacrifice, and martyrdom, and to get used to reciting them eloquently, in a tone where he imitates these heroes.
It is also useful for him to watch meaningful Islamic animated films with heroic themes, such as "Muhammad Al-Fatih" and the film "Wa Islamah," and other educational and inspirational films.
4- And the most important of these steps: The father should take the boy to men's activities, men's gatherings, and men's meetings, especially in mosques, Islamic centers, and righteous environments. He should ask him to introduce himself to the men, to greet them, to look them in the eyes, and to express himself confidently.
This regular accompaniment and consistent training will transition the boy into the world of men and their ways of bodily expressing themselves.
We ask Allah for your success and protection from tribulations.
And Allah knows best.