OpenVPN minecraft

[Bubbles]

Hi,
I can connect to my home LAN from my iphone on a cellular network via OpenVPN on my rt-66ac running Merlin. When i connect two phones at the same time this works fine too. However, when I start minecraft on one phone and want to join that instance from the other, it can't see it. When at home connected to the LAN via wifi the phones can see each other.

Is there a setting or custom configuration for OpenVPN in Merlin that will let the two phones think they are on the same LAN while out and about on a cellular network?

Maybe something to do with the vpn subnet / netmask? Mine are 10.8.0.0 / 255.255.255.0

Also push lan to clients is enabled as well as direct clients to redirect internet traffic.

I have tried adding client-to-client and push "route 192.168.10.0 255.255.255.0" to the advanced custom config box.

Edit: I think I need server-bridged and dev tap rather than tun and probably need a different vpn subnet but now I'm lost!

Edit2: It appears tap isn't possible on iOS devices. So is it possible to do client-to-client with tun?
Thanks!