Meeting topic changes to an old one

When I create a new meeting, and type in the topic, it frequently defaults to a previous topic I used several years ago. Also, if I go to a meeting I've already scheduled, including a recurring meeting, and make a change somewhere in the settings, the topic default back to the same old topic. I used several years ago. It seems to be stuck in that somehow as a default, although it's no longer relevant. I've not been able to find any articles which address this.