@yubik 

When you say it worked for you over wifi, do you mean your own internal wifi or wifi from somewhere else?  Testing from your own internal wifi isn't a valid test.  If it works on wifi outside your network, it should work on cellular as well.

 

What does your OpenVPN config look like?  It would be helpful if you screen shot the config and post it here.  There's nothing on the config page that's sensetive from a security perspective, just don't export the config and post it here!

 

Lastly, what are you trying to accomplish in the end?  If you're just looking for some basic remote access to your network, OpenVPN is very simple to setup and works well.  If you are expecting to do any large file transfers or other high bandwidth applications, it's going to suck terribly.  Due to how resource intensive OpenVPN is, you won't get much speed out of it.  Wireguard is by far the fastest option...though the implementation in the Omada routers is horrible!  If you opt for the Wireguard option, it's best done on a Raspberry Pi, a NAS, or something else on your network.  There is a bit more of a learning curve to get it setup though they've made it pretty simple in PiVPN if you can do it on a Pi.  You would then just setup a NAT rule to forward the Wireguard port to whatever device you run it on.

The open vpn client work on my network only I want to be able to connect through my VPN on a cellular network any where I want connect through my LTE phone.

  @yubik 

 

Ok, please post a snapshot of your config so we can help determine if it's correct or not.