We use Crowd to manage users from Active Directory. So Crowd is much preferred than integrating Jenkins to the AD directly.

In the field, Group name/s for users, since the group separator is either space or comma, then it is impossible to have groups with spaces in the group name.

Example data: "Blah Group"
This "Blah Group" exists in the AD.

When Checking the connection, it failed with:
The group '"Blah' does not exist or is not active.