Must I perform Friday Prayer with the congregation I have caught up with, thereby nullifying the Dhuhr prayer I performed alone, or is it sufficient for me to keep the Dhuhr prayer?

If a person enters his usual mosque and finds that people have left, and he thinks that Jumu'ah prayer has ended in nearby mosques, so he prays Dhuhr, and then it becomes clear to him that there is another mosque still performing Jumu'ah, then he is not obliged to pray with them. However, if he prays with them, it is better and more cautious. But if he missed the prayer in his mosque and knew that there were other mosques where the prayer had not yet finished, then he must pray Jumu'ah with them.