What's the output of ifconfig, when the phone is connected via USB?
ifconfig enp0s29u1u1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168.2.20 netmask 255.255.255.0 broadcast 192.168.2.255 inet6 fe80::ca60:7701:f7f0:40cf prefixlen 64 scopeid 0x20<link> ether 4e:09:fb:0e:f3:5a txqueuelen 1000 (Ethernet) RX packets 2 bytes 656 (656.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 51 bytes 8717 (8.7 KB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 enp17s0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500 ether 84:2b:2b:80:6e:3d txqueuelen 1000 (Ethernet) RX packets 0 bytes 0 (0.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 0 bytes 0 (0.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10<host> loop txqueuelen 1000 (Local Loopback) RX packets 3241 bytes 301291 (301.2 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 3241 bytes 301291 (301.2 KB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 wlp18s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168.1.86 netmask 255.255.255.0 broadcast 192.168.1.255 inet6 2a00:23c4:6697:9800:3386:413b:33eb:e9a7 prefixlen 64 scopeid 0x0<global> inet6 2a00:23c4:6697:9800:d584:5ba9:3733:61ba prefixlen 64 scopeid 0x0<global> inet6 fdaa:bbcc:ddee:0:d584:5ba9:3733:61ba prefixlen 64 scopeid 0x0<global> inet6 fdaa:bbcc:ddee:0:9b49:3166:84b:52e0 prefixlen 64 scopeid 0x0<global> inet6 fe80::56b6:b68e:a450:3b3f prefixlen 64 scopeid 0x20<link> ether 5c:ac:4c:7f:17:0c txqueuelen 1000 (Ethernet) RX packets 29913 bytes 29938016 (29.9 MB) RX errors 0 dropped 0 overruns 0 frame 195558 TX packets 24044 bytes 3392690 (3.3 MB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 device interrupt 17