I found the problem:
In my AD I have organization units with " /" - this sign makes problems with ldap sync.
I changed the OU i.e. “trainees/interns” to “trainees-interns” and now it´s runing correctly.
Rename your OU, clear cache and click in “users and groups” -> “Users” in your admin console, then the ldap sync should restart.
In addition to this, I set max pagesize to 2000 in AD.