Hi, Guido Ardizzone
Welcome to Microsoft Community.Thank you very much for taking your valuable time to contact Microsoft Community Support and share with us what you are experiencing when using OneDrive shared folders. We fully understand the inconvenience you describe with shared folders showing up as shortcuts, and we value every detail of your feedback.
Regarding the issue with OneDrive shared folders showing up as shortcuts, we understand that this has become a hot topic of concern for many users. Currently, this issue has been logged by the OneDrive team and is being actively investigated and fixed. Once the issue is resolved, .url Internet shortcuts will be automatically converted back to folders.

You can check out the specific information at this link.
Add and sync shared folders to OneDrive for home - Microsoft Support
Please understand that since these types of product functionality issues need to be handled by OneDrive's engineering team, our community members are unable to directly intervene or provide specific solutions at this time.
Please try to access the shared folder temporarily via this link until the issue is resolved.
https://onedrive.live.com/
Again, I apologize for any inconvenience this issue may have caused you.
If you have any questions or need further assistance, please let us know.Best Regards,Kyra – MSFT | Microsoft Community Support Specialist