L2TP with Mac not Working

Hi, I’ve setup a VPN using L2TP for remote client access. The VPN connects fine and I can get into the Balance One, but not the other devices on the LAN. The VPN gets a proper LAN IP, is set to move all traffic on it, but can’t even ping a device other than the Balance One. I’ve tried inbound rules as well.

There was a post with the same issue about 4 years ago and the solution seemed to be related to adding SMB (port 139, TCP) and AFP (port 548, TCP) to the Balance One, but the explanation was not clear, so I do not know where to add these services.

Any help will be much appreciated. Thank you.