Well not so much the adress of the AD server.
It should be the domain name of your domain that you have created.
As in Joh.Doe@CompanyWork.internal
The part behind the @ is the domain the user is registered to and even though the AD server might be named prod-ad-001 the text should be the domain you are trying to auth towards and the share you are accessing to should obvioisly have a connection the the AD to forward the credentials and ask if Auth is positive.
Just for the sake of testing maybe try it with a oneliner:
sudo mount -t cifs -o user=testuser,domain=testdomain //192.168.1.100/share /mnt
Either way using the logs is the best way to check for discepancies. Also check in on the logs on the fileserver. Though idk what to advice to trace the logon stuff and trace whats making it fail.
Just for the case that you dont know where to look in windows: eventviewer is the place to go. Which predifined filter though - simply google that.
Wishing ya the best of luck mate!