Hey RamikK!
Perhaps your contacts database on your Mac needs to be reset, if so, you can follow these steps:
First, export any contacts you have as a backup:
Export or archive contacts in Contacts on Mac - Apple Support
I’d do this for all accounts, (Although it appears you only use iCloud for contacts).
If not all are showing in the Contacts app, you can also save a copy from iCloud.com:
Archive or make copies of the information you store in iCloud - Apple Support
And this is just a precaution, next:
Disable any accounts in System Settings > Internet Accounts, for just Contacts.
Quit the Contacts app.
Then Open Finder. While holding Option on the keyboard, on the top menu click Go > Library, to access the user library.
From there, delete, or keep a copy, then delete any folders named Address Book or Contacts, or any files named com.Apple.addressBook.plist from the following folders:
Application Support
Containers
Preferences
Preferences / ByHost
Saved Application State
Next, restart, open the Contacts app, (It should be empty), then enable your contacts again from your accounts in System Settings > Internet Accounts. They should start to populate.
Before doing this, if you want to be sure your user account is the problem, you can create a new user account, sign into iCloud and test, if all works just fine, then it’s most likely a user account database issue, or a user permissions issue. In that case, I’d follow the steps above, and see if resolved. Hope this helps!
Add a user or group on Mac - Apple Support
If that doesn’t resolve it, let me, or anyone else here know and we’ll do our best to help out!