Is it permissible to restrict the publication of religious benefits and advice to women only on an Instagram page due to men following it, along with the fear of designs appearing that suggest the gender of the publisher, and the publisher's desire not to deprive men of benefiting?

There is no harm in men following your da'wah (preaching) page, and there is no need to block or prevent them, especially since the page is for publishing and not for conversation. Similarly, there is no harm in making the page exclusive to women. We pray that you are rewarded for your call to Allah, as striving to teach people and enlighten them with the rulings of Sharia is one of the greatest acts of devotion to Allah the Almighty. Allah the Almighty says: "And who is better in speech than one who invites to Allah and does righteousness and says, 'Indeed, I am of the Muslims.'"