In 1.3 rolling the interfaces openvpn <intf> tls auth-file <filename> does not write the key direction to the OpenVPN config.
It only adds tls-auth <filename> where it should add tls-auth <filename> <key-direction> (0 for server and 1 for client)
This can be worekd aroudn by adding something like openvpn-option "tls-auth /config/auth/shared.key 1"
I would be happy to add a bugfix for this.