Starting from 23 Dec 2021, we are not able to update any of the Adobe XD prototypes created from the XD files created after this date. We may only create new prototypes without the possibility to update them.
How to replicate the issue:
Create a new XD file - place an artboard (it might be empty).
Create a share link
Visit the given link on your web browser.
Back to Adobe XD, add some changes to the existing artboard, and click 'Update link'. You will get a message under the link: 'Updated today at [date]'
Back to webrowser and check updates: Not changes were applied, the date is from the moment when you created the sharable link.
Adobe XD 18.104.22.168 and Creative Cloud Sync 22.214.171.124 (Win 10).
Summary: Prototype updates are working on older files than 23 Dec 2021 - For those, we can easily perform updates.
New files are simply not supported. My Team can't provide changes to design and redistribute it to developers. We are waiting for help.