Great News! Everything is working perfectly. I ended up finding a troubleshooting guide:
https://www.samba.org/samba/docs/usi...HP-12-SECT-2.6

I started from the beginning and re-worked my hostnames and hosts files on all machines on the network. Then I just went through step by step. By the time I got to "Testing Browsing with smbclient" I ran into NT_LOGIN_FAILURE. I also noticed that I had two errors in my config file.

I corrected the two errors, one was a typo and the other samba didn't seem to like so I took it out. And, voila!

After a restart of smb and a reboot on the clients everything is up to speed!

Thanks for helping!!! You got me looking in the right places.

Is this the same hardware you were using on the last server?

Great ....
Ohh i see. u must have not run testparm which would point the mistakes in smb.conf file.
Anyway congrats

And thanx for sharing link.

thegwer, yes everything is the same. The only thing that changed was the OS.

zafar_dandoti, I did run testparm but didn't notice any errors previously, and the logs didn't show anything.