They are on different subnets with wired vs widi. You need a switch to hand out IP to all devices instead letting the wifi and modem do them separately
Discussion
Any idea where these settings might be found?
Without buying new hardware best bet is to try to login to your wifi router and see if you can somehow allow it to use your Ethernet modem to assign the IPs
Another thing you can look into is tail scale which would allow you to access everything through the Internet instead of the LAN
First check ip addreses on your devices