Dear Alison,
Regarding "Microsoft 365 apps for enterprise, version 2310, 64-bit", could you upload a full screenshot of the Account page in the Word app you're using for our reference as we'd like to know the detailed version number information in your environment. You can access the page by clicking on File>Account.
Meanwhile, upload some related screenshots of the issue for our reference so that we can know the situation in your environment.
Note: Delete any private information before uploading the screenshots.
What link are you using? Could you also provide the link you are using for our confirmation?
Welcome to share any updates when you have time.
Thank you for your effort and time.
Sincerely
Cliff | Microsoft Community Moderator