Mac mini Server - Issues with broken permission rights

I currently have a big problem with access rights on a Mac Mini that acts as a server. Various folders are suddenly visible to all users even though they are not included in the file shares. I removed the folders from the share as a test and did the same with the users. I also reset the ACL rights via the terminal but the problem still exists. Newly created users also have full access to the files. The Mac Mini is currently running Ventura version 13.5.2 (22G91)

Any kind of help is great