Hi!
FYI I have a GL-AR750
It seems whenever openvpn connects, it resets the firewall configuration for the openvpn zone, specifically it set’s the “froward” to Reject.
I had previously done a work around to this last year after suggestion here: AR750 OpenVPN DIsconnects and Firewall
Unfortunately I just upgraded to version 3 of the firmware (looks nicer :D) and can no longer find what to update. Can you point me in the right direction please? 
(and can I request maybe allow the option via GUI in the future? )
Thanks!