At the moment, the current configuration is not entirely clear. You mentioned that you attempted to use port forwarding, which would not be necessary if a VPN is configured correctly. To help us better understand the setup, could you please provide screenshots of your current configuration? Screenshots of the panels configuration (including default gateway settings, etc.) would also be very helpful.
I changed subnet to 255.255.255.255 and masquerading to on under zones.
No change, I can connect to 192.168.255.10 and do get a hold of 192.168.1.12.
Issue is that https redirects to http when I connect through VPN. Siemens Unified does not accept http due to error in transfer of certificate through the VPN.
So I can open landing page in http. The link to login is in https, but changes to http. And from then on, it is an ongoing loop.
First, please clarify whether you’re using OpenVPN or RMS VPN Hub as these are configured separately, and quite differently (one is harder, one is easier to configure). This would help me to troubleshoot the issue further.
Next, if you’re using the Teltonika RMS VPN application, could you please try to use OpenVPN Connect application instead to see if that resolves the issue?
More so, if you’re using RMS VPN Hub, please delete the Static Route you have in your WebUI, as that is not needed.
Also, if you have a separate OpenVPN configuration on your device that does not come from your RMS VPN Hub (which is automatically pushed onto the device) - kindly either delete it, or disable it so it doesn’t hinder the connection.
*Additional note - no port forwards, traffic rules & such need to be changed, at most, you’ll just have to enable Masquerading under Network → Firewall → Zones, specifically for the LAN=>WAN (first one in the list) zone.
Please also try re-pushing the OpenVPN configuration onto your device from the RMS VPN Hub configuration menu: