Citando Alan DeKok <aland@deployingradius.com>:
It's difficult to see how this is a configuration issue. The fact that things break when the VPN goes down means that the issue is the VPN going down.
Either Samba is breaking, or Active Directory is breaking.
VPN can go down for a lot of reasons, when our internet link is down, when the main campus internet link is down, when something between the two cities are down. We don't want to depend on remote servers to authenticate users, thats why we have a local domain server. All the other campus works with their local domain controllers and Microsoft NPS or Cisco ISE, and all the campus have the same AD config as ours. The only difference is that we use freeradius and samba, you said there is nothing in freeradius that could affect this so there must be something in samba. I think I will post this issue in samba lists then. Thanks for the help.