Dear KT_153,
Good day! Thank you for posting to Microsoft Community. I am happy to help you
I did the test, and the cross-references I added did not include dashes, you can refer to my test screenshot:

I want to make sure that your number Settings are the same as mine. One possibility I can think of is the inclusion of dashes in the numbering Format Settings

Home-Number Format:

If you have checked the numbering format but are still experiencing this phenomenon, I would also like to further confirm the following to help you fix this issue.
If you create a new document, will the same situation occur? If the new document is fine, try copying and pasting the text into the new document to see the effect.You can copy some of the content first (keep the text format only).
If the new document also appears with dashes when the cross-application is added, I would like to confirm the version information of the Word application you are using, which will help me to investigate further:
File- Account-Product inforamtion:

I look forward to your reply. Thank you for taking the time to work with me on this issue
Sincerely,
Tin | Microsoft Community Moderator