Must I make up for fasting the 28th of Ramadan, 1422 AH, which I broke while traveling because I thought the sun had set, then heard the call to prayer a few minutes later?

Your fast is valid if you broke it based on your observation of the sun's disk setting, and there is no consideration for the call to prayer (adhan), as Allah says: "Then complete the fast until the night." However, if you did not see the sun, you must rely on what indicates sunset, such as the adhan or the calendar. If you broke your fast without seeing (the sun) or relying on an adhan or a calendar, and then the adhan was called after you broke your fast, you must make up that day.