I plug my cable modem into a server running the OPNsense firewall [0], which has a wireguard plugin.
I set up a wireguard VPN in OPNsense.
Then I downloaded the wireguard app in F-Droid, and pasted my credentials from the wireguard Android app into the wireguard configs on the firewall.
I set the VPN in grapheneOS as "always on," so from my phone's perspective, it always has access to my internal network, even when on LTE. All my phones internet traffic ends up going through my home internet connection as a result.
I set up a wireguard VPN in OPNsense.
Then I downloaded the wireguard app in F-Droid, and pasted my credentials from the wireguard Android app into the wireguard configs on the firewall.
I set the VPN in grapheneOS as "always on," so from my phone's perspective, it always has access to my internal network, even when on LTE. All my phones internet traffic ends up going through my home internet connection as a result.
[0] https://opnsense.org/