Problem logging LDAP synced users for the first time

I’m thinking about suggesting Seafile to one of my clients, so first of all, I’m trying it myself (Pro version 6.0.5 with 3 users limitation).
I deployed it but I have a problem with LDAP sync:
After I synced it manually with my LDAP, the user has been added to CCNET Database (I can see the user in LDAPUsers section when exploring ccnet DB in MySQL workbench software)
But I can’t log in with any password. It’s saying “Incorrect email or password” . I can’t even reset the user password that has been added after configuring e-mail notification ( it’s showing: "Can not reset password, please contact LDAP admin).

the DC that it’s syncing with is a windows server 2012 R2 Std.

I’d appreciate your help!