@Kevin_Z Thanks for the input. I think I found what caused this behaviour. I still had the OpenVPN option attached to the same port as I was trying to forward. So I disabled OpenVPN inside the router...

So I set up my VPN server in my SOHO so I can access my openmediavault machine and files from on the go. I set up port forwarding on the router to forward a port to my VPN server ... as you would....