Hi April,
To isolate your concern, we'd like to know if this issue with embedded objects only happens to a certain file. Have you also tried to add an alternative text to a different object? If so, did you still have the same issue?
In the meantime, I'd recommend installing the latest Office updates.
Keeping your Office application up-to-date ensures that you'll get new and improved features, latest security updates and fixes too.
Once you have already installed all latest updates, you may try opening Word in safe mode to check if a certain add-in is causing the issue. If the issue still persists when you launch Word in safe mode, you can try to repair Office. For more information, go to Repair an Office application.
If you continue to have this issue even after performing the above steps, please reply to this thread. The system will notify me so I can get back to you and provide you with more answers.
If this resolves your issue, please indicate “Yes”, so that other learners can benefit, and please take our short survey to let us know if your support experience has been great or how we can improve.