iPhone network question for you:

I have a VPN server at home to access my local LAN when not at home.
It works correctly from Windows, OSX, and Android.

When I connect to it using my iPhone VPN built-in client, my iPhone decides to route ALL traffic through that VPN tunnel. This is not a welcome behavior because my VPN server is configured NOT to route traffic back to the internet (that's not what my VPN server is there for), but to confine it to my LAN.
So, when connected to my LAN via my VPN server, the iPhone correctly reaches all local resources (i.e. file shares, cams, home automation various devices, etc.), but stops being able to go anywhere on the internet - so, no browsing, no email, no social media, no messaging of any sort.
Of course, by disconnecting from my VPN, all goes back to normal.

Not ideal.

My guess is that the iPhone stops using the correct gateways it must have in its routing table (WiFi's and/or Cellular Network).

Any suggestion on how to solve this? I can't even find a way in IOS to see the iPhone routing table. Let alone configure it.

Repeated searches online did not help much.

Thanks! And Happy 2020!


P.S.: I did, as an experiment, try reconfigure my VPN server to allow routing traffic to the internet, and it "worked", so to speak. My VPN server can push routes to the clients' routing tables, and the iPhone seems to get those. So I did, and my iPhone could access the internet via my home network/isp, of course; that had some side effects on Windows and OSX (did not test with Android) which I had to fix, but still, I don't particularly like the idea of hav ing my iphone route all Internet traffic through my home network and ISP when connected to the VPN.
Ideally, I'd like to simply configure the iPhone's routing table.