[SOLVED] Unable to sync contacts

Hi all, I have a LG G4s smartphone.
I syncronize with a zimbra server hosted in my office by z-push and the zimbra connector.
z-push version: 2.1.3-1892.
zimbra backend version: 59.

My colleagues have no problem syncing.
I get these error in the log when I try to sync my LG:

19/10/2017 16:35:42 [29115] [INFO] [pbds] Version='2.1.3-1892' method='POST' from='91.252.96.225' cmd='Sync' getUser='pbds' devId='lgmce6xtm2jchkvo' devType='LGPhone'
19/10/2017 16:35:42 [29115] [WARN] [pbds] Zimbra->GetUserInfo():   Overriding ZIMBRA_URL [http://192.168.2.113] from config.php with ZIMBRA publicURL [https://mailserver.localdomain:443]
19/10/2017 16:35:42 [29115] [WARN] [pbds] Zimbra->GetUserInfo():   Overriding  Logon URL [http://192.168.2.113/service/soap/] with ZIMBRA soapURL [https://mailserver.localdomain:443/service/so
ap/]
19/10/2017 16:35:42 [29115] [INFO] [pbds] NoHierarchyCacheAvailableException: Folderid 'f7' is not fully synchronized on the device - code: 0
19/10/2017 16:35:42 [29115] [INFO] [pbds] Full device resync requested
19/10/2017 16:35:42 [29115] [WARN] [pbds] Not possible to determine class of request. Request did not contain class and apparently there is an issue with the HierarchyCache.
19/10/2017 16:35:42 [29115] [WARN] [pbds] Ignoring all incoming actions as global status indicates problem.
19/10/2017 16:35:42 [29115] [INFO] [pbds] Version='2.1.3-1892' method='POST' from='91.252.96.225' cmd='FolderSync' getUser='pbds' devId='lgmce6xtm2jchkvo' devType='LGPhone'
19/10/2017 16:35:42 [29115] [WARN] [pbds] Zimbra->GetUserInfo():   Overriding ZIMBRA_URL [http://192.168.2.113] from config.php with ZIMBRA publicURL [https://mailserver.localdomain:443]
19/10/2017 16:35:42 [29115] [WARN] [pbds] Zimbra->GetUserInfo():   Overriding  Logon URL [http://192.168.2.113/service/soap/] with ZIMBRA soapURL [https://mailserver.localdomain:443/service/so
ap/]

Notice that I was syncing 2 account, then I tired to remove one.
I also tried

z-push-admin -a remove -d <id>
z-push-admin -a fixstate
z-push-admin -a clearloop

z-push-admin -a resync -t contact -d <id>
Resync of 0 folders of type contact on device 'xxxxxxxxxxxxxx' of user 'pbds': ZPushAdmin::ResyncFolder(): no folders synchronized for user 'pbds' on device 'lgmce6xtm2jchkvo'. Aborting.

z-push-admin -a lastsync | grep pbds
lgmce6xtm2jchkvo     pbds     never

I need to sync these contacts.
Any idea?

Reading more carefully the log, I noticed

Zimbra->Logon(): FATAL: Zimbra Backend Requires PHP-CURL

I was missing php-curl.
So

apt install php-curl
phpenmod curl
systemctl apache2 reload