I tested on Opal with firmware 4.3.6 RC2.
The setting “Services from GL.iNet use VPN” has no effect.
The router IP as shown in Goodcloud is always that of the VPN while the VPN is active. This causes issues with web access to the router through Goodcloud, presumably because the VPN interferes with the rtty protocol you use for this purpose. The web access login links already look abnormal to begin with, like so:
goodcloud.xyz/web/<device_id>/127.0.0.1/%3A/80/
This results in displaying a blank web page.
Please look into how to make the setting to bypass VPN for GL services work as described.