Contacts in the phone are not deleted

[Kirill2405]

Sync works fine. Contacts in the phone are updated and added.
But when you delete it on the server, the contact remains on the phone.
Also, when deleting a contact in the phone, during subsequent synchronization with the server, the contact does not appear.
The logs show:
Delete contact: cn=name ... but on the phone he remains
Update contact: cn=test ... but it doesn’t appear on the phone since it was deleted from the phone book
How to solve this problem?

[luelista]

I only resurrected this app and changed some stuff to make it compatible with new android, but I haven't yet dived into the details of the syncronisation mechanism itself. So I don't really know how it's supposed to work, or why it might not work.

That said, there is some deletion code in the ContactManager, which prints the Log messages you mention:

https://github.com/max-weller/LDAP-Sync/blob/f8e30c57cbc5c30ad68a715802f9bd36458aaf52/app/src/main/java/de/wikilab/android/ldapsync/platform/ContactManager.java#L102-L108

However, if deletion fails, it seems to just Log an error message and carry on:

https://github.com/max-weller/LDAP-Sync/blob/f8e30c57cbc5c30ad68a715802f9bd36458aaf52/app/src/main/java/de/wikilab/android/ldapsync/platform/ContactManager.java#L268-L269

Where did you get the log output from? adb logcat? Or the builtin text log file which is written to the sd card?
Because the builtin one seems to be incomplete. Maybe have a look at the logcat output then.