[Samba] Not using AD group when writing file

[Carl Carpenter]

Centos 7
Samba 4.1.1

Trying to get Samba configured correctly.  Am using Active Directory for
authentication and that seems to be working correctly.  When creating a
Share, Security and Access Control list the AD users and groups.  If I take
my name out of the AD group, can't access the share.  Put my name in the
group and I can access it.  However, when I write a file to the folder,
while it shows my username, it shows domain users as the group instead of
the group name.  I had this working on Centos 6.6 and am using the same
instructions this time.  I'm sure I'm missing a setting somewhere but don't
know what.  Haven't been able to find anything on the web that addresses
it.  Any assistance will be appreciated.