Hi,
Thanks for sharing here!
It may caused by the ABE set on the folder.
Access-based enumeration hides files and folders that users do not have permissions to access.
When the Access-Based Enumeration has been enabled for the shared folder , and users don't have read permission for some folders within the shared resource, then the folders can't be seen .
For more information , you can refer to :
https://techcommunity.microsoft.com/t5/ask-the-directory-services-team/access-based-enumeration-abe-concepts-part-1-of-2/ba-p/400435
Best Regards,