Dear Christian,
Good day! Thank you for posting to Microsoft Community. We are happy to help you.
As per your description, it seems that you are having issue with "citations & bibliography" function in Word, the citation only appears as plain text and the tickmark next to the source in the "current list" does not appear next to the source.
If the understanding above is right, to help you better, we would like to collect more detailed information you're experiencing so that we can have a further investigation:
- Would you please share some screenshots of the issue with us?
- Please also share your steps with some screenshots.
- Does this happen to all files or the specific file?
- Please also share a screenshot of the Word version as shown below by opening Word app > File > Account

Appreciate your understanding that sometimes the initial reply may not resolve the situation very soon. However, we can work together to narrow down and resolve the situation. Please kindly post back and provide the more information, then we can focus on your specific scenario and provide specific suggestions.
If the understanding above is not consistent with yours, please feel free to post back and point that.
Your understanding and patience will be highly appreciated. We hope that you are keeping safe and well!
Thanks for your cooperation.
Sincerely,
Rhoda | Microsoft Community Moderator