Yes, "auto logon" is enabled, but, "auto logon" enabled or not, the problem still the same.
Logoff / re-logon doesn't work either.
The relatable community thread indicated doesn't help me and conclusions are not clear… It seems doesn't works fine all the time (not like when user is Added explicitly).
One thing is sure, if you add explicitly the user (member of the group) in security rights of the adressbook, it works fine immediatly you valid the modification (therefore, it's not a RU server connection problem…).
If you remove the user and valid the modification, logoff and re-logon, then synchronisation doesn't work again...