Why are some users able to log in and others not?

ygorsm

Hello.

I manage a Sonicwall Supermassive 9600 generation 6.5, I configured it for authentication via an LDAP server, it is UP and I can import the groups, the problem I am having is the following:
I have 2 users who are in the same group in AD, "GR_Default_VPN" for example, this group was imported into sonicwall via LDAP, and a VPN Access permission was configured for this group.

Of these 2 users who are in the same group, only one of them can access Global VPN and the other cannot, why does this happen? Since the 2 users are in the same group and have the same permissions settings?

What I noticed by going to Users > Settings > Configure LDAP > Test > LDAP search.
When placing a user in the search, it brings me all the information about that user and also the groups they are a member of (memberOF: CN=GR_VPN_Default,OU=Access Groups,DC=uninove,DC=br), however, for the other user, of the information that is brought, only the groups in which the user is a member do not appear.
I don't know if that would be the reason, but from several users that it doesn't work and others that work, there is this difference.

Has anyone faced this problem or have any idea what steps I should take to try to resolve it?