Yes, off-campus activities can become the subject of a college sexual misconduct investigation or case. Title IX narrowed its focus with the Title IX Final Rule that went into effect on August 14th, 2020. Although certain forms of misconduct will no longer be covered under Title IX, the Title IX Final Rule has not only allowed, it arguably encourages schools in a sense to continue to address and adjudicate sexual misconduct that takes place outside of Title IX Final Rule's scope.
Many cases of college sexual misconduct occur off-campus, be it in an off-campus apartment or even in an overseas program, and either countless ways that college students interact off campus can become the subject or the venue for where sexual misconduct allegations can take place. For that reason, just because the Title IX Final Rule is more narrow in scope, schools will still continue to be addressing misconduct, but in many instances, they'll be doing so through their college sexual misconduct policies, not necessarily their Title IX policies.
That's why it's important to be mindful of that. A person can definitely be subject to investigation and adjudication by their school through such policies. An experienced attorney advisor can help navigate the process and can protect an accused person's rights and interests through the process.